CEMENT  WORKERS' 
HAND-BOOK 


COVERING  MORE  THAN  Fir TY 

|      MOST  IMPORTANT  SUBJECTS      J 

ON  CEMENT  AND  ITS  USES 

IN  CONSTRUCTION 


COMPILED    TO    MEET   THE   REQUIREMENTS 
|  OF   THE   COMMON   WORKMAN 

BY  W,  H.  BAKER 


Published  By 

£  SOUTHERN  ARCHITECT  AND  BUILDING  NEWS 
843  Equitable  Building 
ATLANTA,  GA, 


f  PRICSS  SO  CENTS 


GIFT  OF 
1  R/.Y  B.S.16  XX, AZ 


•,•..,..... 

1  Cement  \Vorker's 
Hand-Book. 


A  Practical  Treatise  on  Cement  and 

li 

its  use  in  Construction. 


|  Compiled  to  Meet  the  Requirements  | 

1  1 

of  the  Lay  Workman, 

* 


W.  H.  Baker. 


Published  by 

Southern  Architect  and  Building  News, 
Atlanta,  Ga, 


»  ••  -     .,  t     • 

-    •  •  - '  •>  «     •        < 

•.' "  .    .        \J 


NOTICE 

The  author  feels  indebted  to  S.  B.  Newberry, 
E.  M.,  Ph.  D.;  Adolph  Cluss,  F.  A.  I.  A.,  and  others 
for  much  valuable  information. 

Also  to  "Portland  Cement  und  seine  Anwendun- 
^gen  im  Bruwasen,"  and  "Das  Kleine  Cement  Buch." 
The  two  books  that  represent  the  latest  and  best 
thoughts  on  this  subject  in  Germany,  and  perhaps 
in  the  world. 

/hade  /,- 


*/ 


Copyrighted,  April,  1906,  by  W.  H.  Baker 
All   rights   reserved. 


PREFACE 

The  present  generation  has  witnessed  a  marvelous 
growth  in  the  uses  of  hydraulic  cements.  And  had  the 
workmen  in  its  manipulation  kept  in  step  with  the  con- 
stant and  rapid  evolution  in  its  manufacture  it  would 
have  still  more  completely  revolutionized  building  and 
the  materials  used  in  general  construction. 

In  1882  only  185,000  bbls.  of  Portland  Cement  were  used 
in  the  U.  S. ;  in  1902,  one  decade  later,  17,230,000  bbls.  were 
used.  Today  in  one  district  of  the  U.  S.  covering  100 
square  miles  alone,  there  are  20  mills  with  an  output  per 
year  of  11,000,000  bbls.  of  Portland  Cement. 

The  chemical  and  physical  makeup,  and  consequently 
the  nature  of  cement  was  often  misjudged  by  the  workman, 
resulting  in  work  the  most  crude  and  unsatisfactory.  Not- 
withstanding this  condition  of  things,  its  generally  recog- 
nized desirability,  the  multiplication  of  its  uses  and  its 
demonstrated  durability,  have  won  for  it  the  favor  of  the 
best  engineers  and  architects  of  the  day.  Its  rapidly  in- 
creasing use  has  surpassed  the  predictions  of  its  best 
friends.  "Cement  and  steel  are  to  be  the  building  mate- 
rials of  the  future."— Thos.  A.  Edison. 

Before  the  American  Institute  of  Architects  Adolf  Cluss 
stated,  "That  in  the  building  trade  cement  must  be  reck- 
oned with  as  one  of  the  foremost  components."  For  the 
reasons  stated  a  more  practical  knowledge  of  its  nature,  and 
the  workmanship  in  its  application  is  greatly  to  be  desired. 

For  twenty  years  (as  a  mason)  I  have  had  a  varied  ex- 
perience in  the  uses  of  cement,  and  must  say,  as  perhaps 
would  many  an  honest  fellow-workman,  that  I  have  con- 
stantly felt  hampered  by  the  want  of  more  practical  knowl- 
edge in  this  line.  Though  careful  that  I  might  add  to  my 
scant  knowledge  by  experience  and  observation,  yet  no 
doubt  there  were  defects  that  with  the  same  materials,  but 
by  more  skillful  handling  could  have  been  averted.  The 
amateur  workman  in  cement  always  flies  to  the  conclusion 
that  what  he  larks  in  experience  he  can  readily  make  up 
by  extra  quantities  of  cement.  Yet  what  is  further  from 
the  truth?  Even  dangerous  and  expensive. 

During  this  time,  by  constant  effort,  I  was  enabled  to 
find  but  few  books  and  a  few  articles  in  trade  journals 
upon  this,  to  me,  important  subject.  1'hese  were  written- 
for  engineers  and  architects,  and  consisted  in  trade  words 
and  technical  terms  which  though  clear  to  them,  yet  to  the 
average  workman  they  were  obscure  and  meaningless,  plac- 
ing their  application  just  a  little  above  their  comprehension 
or  use.  It  has  always  been  my  contention  that  the  work- 
man who  labors  with  his  back  to  the  sun  should  not  be 
a  mere  machine  in  the  hands  of  the  engineer,  but  that  for 
the  best  results  in  his  craft,  and  for  the  intelligent  con- 
summation of  the  plans  of  an  engineer  or  architect,  he 


must  he  an  intelligent  force,  knowing  the  fundamental 
principles,  the  causes  and  effects,  that  preserve  his  craft 
from  the  unskilled  laborer. 

„  Surely  no  calling  presents  a  more  exacting  bid  for  skill, 
and  in  no  calling  can  the  want  of  it  produce  greater  harm 
or  ruin.  Hence  this  little  treatise,  written  for  the  hum- 
blest workman  by  a  fellow-workman.  We  have  not  written 
because  we  felt  most  competent  to  do  so,  but  because  we 
have  so  keenly  felt  its  need. 

We  aim  to  make  this  little  book  so  simple,  so  clear,  and 
fundamental,  that  the  farmer  and  others  not  familiar  with 
cement  may  do  much  of  their  own  work,  confident  of  suc- 
cess, while  the  more  difficult  work  in  this  line  must  of 
necessity  go  to  the  regular  cement  worker,  or  mason. 

Should  you.  after  careful  examination,  decide  that  your 
theory  and  practice  in  handling  cement  cannot  be  en- 
hanced by  our  humble  efforts,  no  offense!  On  this  very 
threshold  we  bid  you  "God  sneed,"  and  may  the  stability 
and  grandeur  of  your  work  be  a  worthy  incentive  to  many 
a  less  fortunate  workman. 

But  it  is  to  you,  my  dear  brother,  who  wishes  to  know 
more  in  this  craft,  that  I  dedicate  this  little  volume. 

W.    II.   BAKER, 

A.   D.,   1903.  Wads  worth,   Ohio. 

After  three  editions  of  the  first  print  had  been  exhausted, 
and  the  continued  demand  for  the  book  having  increased 
so  much  beyond  the  author's  anticipations,  it  was  thought 
advisable  to  revise  the  first  copyright  by  a  few  changes 
and  the  addition  of  some  matter  not  contained  in  the  first. 
The  brevity  and  simple  directness  which  characterized  the 
first  print  and  which  was  so  frequently  commented  on  in 
reviews  of  note,  has  not  been  lost  sight  of. 

It  has  also  been  the  object  of  the  author  that  the  price 
of  the  book,   which   though   not   over   one- fourth   the  price 
of   similar    books   might   not    be  increased,    thus    keeping   it 
within  the  reach  of  the  laborer  for  whom  it  is  written. 
a>April,  1906  W.   H.   BAKER. 


INDEX 


PART   I.  (Page) 

Introduction   to   Commercial    Hydraulic   Cements.. 7 

Historical , 7 

Composition 8 

Properties     9 

Classification 10 

PART    II. 

Mortars     11 

Composition     11 

Mixing  and   Handling 13 

Nature , 14 

Kinds     17 

Neat   Cement    Mortar    17 

Portland    Cement    M'ortar    18 

Natural   Cement   Mortar    18 

Cement-Lime   Mortar    18 

PART  III. 

Concretes 18 

Composition     18 

Mixing    and    Handling    20 

Nature    23 

Kinds     25 

Ordinary  Concrete  25 

Reinforced    or    Armored    Concrete    25 

Liquid    Concrete    29 

Mortar    Concrete    32 

Pulp   Concrete   32 

PART  IV. 

Cast  Masonry  33 

Stationary    33 

Foundations    and    Footings    34 

Walls 35 

Floors   (Supported   on  the  Ground)    43 

Floors   (Supported  on  the  Joists)    47 

Ceilings 48 

Partitions     48 

Walks     49 

Drives     55 

Curbing     55 

Posts     57 

Cisterns 58 

Reservoirs 60 

Grave   Va ults    62 

Culverts     63 

Steps     65 

Portable  Cast  Masonry    67 

Building   Blocks    60 

Pence   Posts    73 

Troughs    ' 77 


>  (Page) 

Tanks     70 

Chimney  Tops   70 

Sewers 81 

Statuary  and  Ornaments   81 

PART   V. 

Practical  Notes  on  Cement  Work   82 

Hair   Cracks    82 

Settling  or   Shrinkage  Cracks    8:J 

Pock    Marks    84 

Freezing    Weather 84 

Hot   Weather    83 

Dry  Surface  and   Adhesion    85 

Portland  as  Against   Natural   Cements    80 

Seasoning   Cement   Work    88 

Measuring     Ingredients     88 

Re-working  Mortar  and   Concrete   80 

Forms   for   Cast   Masonry    80 

Filling  and    Polishing  Surface  of  Cast   Products 80 

Coloring    Cement    Work    00 

Testing    Cements 08 

Cost  of  Cement  Work    06 

Four   Methods    of   House   Construction    9f> 

Silos    97 


INTRODUCTORY 
COMMERCIAL,  HYDRAULIC 

Historical  ' 

Hydraulic  cements  antedate  the  Christian  era. 
Mortars  play  an  important  part  in  unraveling  the 
mysteries  of  pre-historic  civilization.  Of  ancient 
Niniva  and  Mantinea,  though  in  their  time  magnifi- 
cent and  powerful,  now  little  is  known.  Their  struc- 
tures of  sand,  dried  clay  and  loam  mortar  have  long 
since  crumbled  to  dust. 

The  contemporaneous  Roman  buildings  were 
built  of  hard  burned  bricks  or  stone  bedded  in  either 
Bitumen  or  Asphalt  pitch.  Recent  excavations  show 
that  these  mortars  show  no  trace  of  disintegration. 
The  Pantheon  at  Rome,  built  with  two  masonry 
faces  filled  with  Puzzolan  concrete,  show  no  unequal 
settling  or  shrinkage  and  but  for  external  causes 
remain  intact. 

The  phenomenal  strength  and  durability  of  these 
Roman  edifices  today  reap  well  deserved  tribute  and 
admiration. 

Approaching  the  "Middle  Ages,"  we  find  that  the 
use  of  hydraulic  mortars  had  given  way  to  fat  lime 
and  silt  mortars.  The  secret  of  these  was  even  con- 
fined to  centers  of  superior  workmanship,  such  as  the 
sites  of  renowned  cathedrals.  This  was  clearly  a 
retrograde  movement,  as  some  of  these  costly  struc- 
tures were  kept  erect  only  by  constant  and  expen- 
sive nursing.  The  mortar  used  in  their  construc- 
tion became  an  inert  powder  devoid  of  strength  and 
hardness. 

About  1757  Smeaton  in  the  erection  of  the  Eddy- 
stone  lighthouse  tower  on  a  reef  near  the  English 
coast,  by  necessity  was  obliged  if  possible  to  find  a 
hydraulic  cement  that  would  resist  the  action  of  the 
turbulent  surf  of  the  coast. 

By  extensive  experiments  he  found  that  the  lime- 
stone from  Aberthaw  which  contained  larger  traces 
of  clay  than  the  others  used  in  the  test,  showed 
greater  cementing  properties  in  water.  .  This  test 
7 


•was  very  important  as  establishing  a  chemical  analy- 
sis favora&le'to  clay/s|licja  and  alumina)  with  lime. 

In  the  year  17%, Tarker, ;  ah  Englishman,  burned 
the  chalky,  clay,  lumps,  on  the  coast  of  England?  and 
from  ft4,  introduced  a  -  superior  cement  called  Roman 
cement  ('because  it  resembled  Puzzolan  in  color). 
This  for  a  time  was  largely  used.  Following  this 
came  such  men  as  Apsdin,  the  English  mason,  Pasly 
and  many  others. 

In  England,  Germany,  France  and  Belgium  fac- 
tories multiplied,  and  each  successive  factory  may  be 
claimed  as  a  triumph  towards  better  results.  With 
the  more  recent  methods  of  calcination  and  grinding 
the  evolution  has  been  rapid.  Physical,  chemical  and 
mechanical  investigations  have  been  carried  on  from 
which  important  tests  have  been  collated. 
COMPOSITION 

According  to  Dr.  Michhaelis,  a  noted  cement  ex- 
pert, the  chemical  analysis  of  good  cement  when 
burned  is  as  follows:  621/&  to  67  per  cent  lime,  and 
33 1/2  per  cent  of  silicates.  This  allows  4  per  cent  for 
accessories. 

The  basic  elements  are  lime  and  clay. 

An  analysis  of  one  of  the  foremost  Portland 
cements  of  the  U.  S.  shows  the  following  elements: 

Silca    20.64  per  cent 

Alumina     6.9.°>  per  cent 

Oxide  of   Iron 5.41  per  cent 

Lime   62.70  per  cent 

Accessories     4.23  per  cent 

The  most  important  process  in  the  manufacture 
of  cement  is  the  vitrification  process  (differing  with 
the  various  mills).  The  constituents  having  been 
pulverized  are  mixed  into  a  homogeneous  paste, 
balled,  dried  and  burned  by  exposure  to  a  quick  white 
heat  equal  to  the  melting  point  of  wrought  iron, 
when  the  mass  approaches  the  point  of  vitrification 
the  heat  is  now  withdrawn  and  the  mass  requires 
rapid  cooling. 

During  this  process  chemical  transformation  by 
complicated  reactions  have  taken  place. 

After  cooling  these  vitrified  clinkers  they  are 
ground  into  a  dense  drossy  steel  hard  powder,  most 
8 


of  which  must  pass  through  a  silk  sieve  of  10,000 
meshes  to  the  square  inch. 

Portland  cement  owes  its  high  reputation  largely 
to  these  physical  changes.  Globulated  textures 
make  contact  by  points,  laminated  textures  by  sides 
or  surface.  In  the  U.  S.  great  strides  in  the  produc- 
tion of  a  superior  Portland  cement  have  resulted  in 
a  great  reduction  of  prices  (formerly  paid  importer 
and  compared  with  which  in  many  cases  it  is 
superior)  bringing  it  into  an  extensive  and  wide 
range  of  uses.  PROPERTIES 

By  nature,  natural  or  common  cements  are  light 
or  dark  gray,  varying  according  to  the  character  of 
the  stone  from  which  they  are  made.  Portland 
cements  are  bluish  or  greenish  gray.  Very  fine 
ground  cements,  other  things  being  equal,  are 
superior  to  coarser  varieties,  carrying  more  sand. 
Cements  have  great  specific  gravity.  Portland 
cements  are  heaviest,  weighing  380  Ibs.  net  per  bar- 
rel of  from  %y2  to  4  cubic  feet;  4  sacks  of  95  Ibs. 
each  constitute  one  barrel.  One  barrel  of  natural 
(or  common)  cement  weighs  300  Ibs.  per  barrel  of 
about  4  cubic  feet;  also  3  sacks  of  100  Ibs.  each  con- 
stitute one  barrel. 

Portland  cements,  especially  if  properly  stored, 
can  be  carried  from  one  season  to  another  without 
loss  .in  quality.  Some  makes  have  shown  improve- 
ment. Long-stored  cements  become  slightly  slower 
setting  but  ultimately  acquire  full  hardness  and 
strength,  but  when  cement  is  stored  where  it  draws 
dampness  sufficient  to  harden,  it  is  damaged  and  in 
some  cases  worthless. 

The  amount  of  water  required  to  work  Natural 
and  Portland  cements  plastic,  varies  with  fineness, 
age  and  temperature,  but  is  approximately  as  fol- 
lows: Neat  (cement  only)  Portland  about  28  per 
cent;  neat  Natural  about  32  per  cent;  one  part 
cement  and  one  part  sand,  15  to  18  per  cent;  one 
part  cement  and  two  parts  sand,  12  to  13  per  cent  of 
total  weight  of  cement  and  sand. 

CLASSIFICATION 

Cements  as  manufactured  today  admit  of  being 
9 


classified  into  two  general  classes,  namely,  Natural 
or  Common,  and  Portland.  For  our  purpose  in  this 
little  treatise  we  will  include  Natural  and  Artificial 
Portland  under  the  one  head  of  Portland. 

Natural  Cement,  in  many  places  better  known  as 
common  cement,  is  produced  from  calcareous  (lime) 
stone,  as  found  in  nature.  It  is  burned  at  a  low  tem- 
perature and  is  afterwards  ground  to  a  fine  powder. 
It  is  less  uniform  in  composition  and  consequently 
less  reliable  than  are  Portland  cements.  They 
usually  show  great  hydraulic  activity  (quick  setting) ; 
they  carry  less  sand  and  require  more  water  to 
hydrate  than  do  Portland  cements,  work  very  plastic 
and  smooth,  and  frequently  show  great  adhesive 
power. 

Portland  Cement,  so  named  because  resembling 
in  color  the  Portland  rocks  of  England. 

Natural  Portland  is  manufactured  in  those  rare 
cases  where  limestone  is  found  which  contains  com- 
binations of  lime,  silica,  alumina  in  the  chemical 
proportion  found  necessary  in  producing  Artificial 
Portland,  from  which  it  does  not  differ  in  mechanical 
treatment.  Natural  Portland  is  still  manufactured 
in  England  and  the  European  Continent. 

Artificial  Portland — This  is  the  cement  in  most 
common  use,  and  which  we  refer  to  in  this  book  in 
all  our  directions  unless  the  natural  or  common  is 
especially  spoken  of.  This  cement  is  considered  the 
highest  grade  cement,  being  entirely  in  the  hands  of 
the  operator  its  composition  can  be  controlled  to  a 
per  cent.  In  this  country  as  elsewhere  it  has  been 
found  that  there  are  many  places  where  limestone 
and  clay  abound,  from  which  the  elements  of  a  good 
artificial  Portland  can  easily  be  obtained.  Conse- 
quently the  recent  cheapening  of  this  best  quality 
of  cement  in  this  country.  This  cement  is  manu- 
factured to  be  either  slow  or  quick  setting  as  desired 
for  special  uses.  After  many  years'  use  of  Port- 
land cement,  tests  show  no  disintegration  where 
they  have  been  properly  used;  they  carry  large  por- 
tions of  sand,  require  less  water  to  hydrate,  are  best 
lor  all  kinds  of  work,  mortar  or  concrete;  submerged 
'  10 


or  in  air  react  all  climatic  conditions  and  it  now 
seems  imminent  that  in  the  near  future  it  will  drive 
the  natural  or  common  cements  entirely  from  the 
market. 

PART  II. 

MORTARS 

In  the  preceding  chapter  we  spoke  of  the  cement 
of  commerce  or  cement  shipped  to  points  for  use  in 
bulk,  barrels  and  sacks.  In  this  chapter  we  shall 
speak  of  cement  as  incorporated  in  sand  and  water 
mixed  into  a  plastic  form  and  used  in  joining  or 
bonding  brick,  stone  and  other  constructing  mate- 
rials, for  plastering  walls,  etc.,  and  is  also  used  to 
form  the  matrix  for  concrete,  etc.,  but  of  this  we 
shall  speak  more  fully  under  concrete. 
Composition. 

The  components  of  mortar  are  cement,  sand  and 
water,  varying  in  proportion  to  suit  the  character 
of  the  work  for  which  they  are  intended.  Much  will 
depend  on  the  character  of  the  sand  used.  Indeed 
so  important  is  this  that  it  is  impossible  to  give 
reliable  and  at  the  same  time  economic  proportions 
for  a  mortar  that  would  be  invariable  when  the  char- 
acter of  the  sand  varies  with  every  location,  and 
sometimes  with  every  job;  so  right  at  this  point 
allow  us  to  specify  what  we  would  require  in  sand. 
It  must  be  clean,  contain  no  clay,  loam  or  soil  de- 
posits; if  these  are  found  the  sand  must  be  thor- 
oughly washed  before  used.  It  must  contain  no  soft, 
friable  or  chalky  particles;  such  sand  should  be  en- 
tirely discarded.  For  economy  it  should  be  irregular 
in  shape  and  size. 

"A  chain  is  no  stronger  than  its  weakest  link/' 
neither  can  cement  work  be  any  stronger  than  its 
weakest  component  part.  The  best  cement  can 
form  no  adhesion  to  soft,  yielding  surfaces. 

Then  from  this  we  conclude  that  sand  must  be 
clean,  hard  and  irregular  shaped  (sharp),  and  varia- 
ble in  size.  Clean  that  the  cement  in  crystalizing 
may  form  contact  or  adhesion  to  surface.  Irregular 
in  shape  that  they  may  pack  more  closely  and  give 
11 


strength  by  interlacing  and  cohesion  to  mass.  Varia- 
ble in  size  that  the  voids  or  spaces  between  the 
larger  grains  may  be  filled  by  the  smaller  ones,  and 
their^voids  again  by  the  cement,  thus  making  a 
dense  and  compact  mass.  By  breaking  a  piece  of 
thoroughly  hardened  cement  mortar  and  carefully 
examining  the  same  on  the  broken  edge  with  a  mag 
nifying  glass  the  process  of  crystalization  and  the 
binding  of  particle  to  particle  can  clearly  be  seen. 

It  must  be  noted,  too,  that  for  proper  cohesion  the 
entire  surface  of  each  particle  incorporated  must  be 
entirely  coated  over  with  cement,  with  so  much  in 
addition  that  the  voids  may  all  be  filled;  any  more 
cement  added  would  clearly  be  a  waste,  and,  not 
only  waste  but  harm,  since  excessive  doses  of  cement 
have  shown  by  many  tests  to  weaken,  ultimately 
causing  rupture  of  cohesion  in  final  crystalization, 
and  yet  what  is  more  common  for  the  inexperienced 
workman,  than  to  "make  sure,"  by  extra  doses  of 
cement.  From  this  the  workman  will  remember  that 
if  the  sand  is  quite  fine  and  uniform  that  more 
cement  must  be  used  than  when  coarse.  The  water 
used  in  mixing  mortar  should  be  clean  and  free  from 
mineral  deposits.  In  preparing  a  few  formulas  in 
which  we  have  reference  to  Portland  cement  only, 
the  proportion  could  be  changed  for  natural  cement, 
where  this  can  be  used,  by  taking  only  two-thirds 
as  much  sand  as  given  for  the  Portland. 

Formula  No.  1. — Cement,  1  part;  sand,  1  to  2 
parts.  This  composition  forms  the  very  best  mortar 
and  would  be  used  only  where  extraordinary  strength 
is  required  or  great  resistance  to  wearing  or  im- 
permeability to  water. 

Formula  No.  2. — Cement,  1  part;  sand,  3  to  4 
parts.  This  last  composition  forms  a  very  ordinary 
mortar  used  in  plastering,  for  bonding  or  brick  in 
building,  for  foundations  and  cast  work.  The  varia- 
tion allowed  in  the  sand  in  each  formula  will  admit 
of  slight  adjustment  to  meet  requirements.  How- 
ever, that  we  may  not  be  misunderstood  in  formula 
No.  1  with  good,  rough  sand  2  parts  sand  to  1  part 
cement  is  equal  to,  and  usually  better,  than  a  mortar 
€  i« 


made  from  one  part  sand  to  1  part  cement. 
Mixing    and    Handling    Mortar. 

Procure  box  of  suitable  size  for  the  work  at  hand 

stiled  mortar  box.     The  boards  should  be  surfaced 

and  bottom  even  so  as  not  to  catch  hoe  or  ^hovel  so 
annoying  to  the  mixer.  The  sand  and  cement  should 
always  be  gauged  and  not  guessed,  or  even  meas- 
ured by  the  shovelful,  as  is  often  done.  For  work 
in  a  small  way  this  may  be  measured  to  procure  the 
exact  proportion  by  either  basket  or  pail.  But  on 
work  of  considerable  proportion  a  box  is  made  by 
which  to  measure  the  sand;  a  sack  of  Portland 
cement  is  taken  as  the  unit,  say  about  1,900  cubic 
inches.  If  the  proportion  wished  to  be  used  is 
cement  1,  sand  3,  then  the  sand  measure  must  con- 
tain 1,900x3  =  5,700  cubic  inches  or  2'x2'xlO"  high. 
The  box  only  requires  sides  and  ends,  no  bottom. 
There  should  be  handles  nailed  across  two  opposite 
sides,  by  which  the  box  may  be  lifted  up  to  empty. 
When  ready  place  measure  box  into  mortar  box  and 
fill  even  full  of  sand,  catch  hold  of  handles  and  lift 
box,  allowing  the  sand  to  spread  over  bottom  of 
mortar  box.  On  this  empty  one  sack  of  cement  and 
with  mortar  hoe  or  shovel  mix  this*  thoroughly 
while  dry.  Now  add  water,  little  at  a  time,  thor- 
oughly working  this  into  the  mass,  until  sufficiently 
plastic  for  work.  Mortar  must  be  thoioughly  incor- 
porated from  corners  and  bottom  of  box.  Tests 
have  been  shown  that  briquet  mortar  in  box  showed 
increased  strength  of  from  30  to  50  per  cent,  hence 
the  importance  of  thoroughly  working.  In  all  work 
it  is  best  to  use  as  little  water  as  possible,  only  to 
make  it  sufficiently  plastic  for  use,  and  this  should 
be  added  a  little  at  a  time,  while  being  constantly 
worked. 

The  mixer  must  also  exercise  care  not  to  mix 
more  than  can  be  used  at  once  or  before  the  first  set 
which  in  slow  cement  is  from  \Vz  to  2  hours.  In 
quick  setting  cement  about  one-half  hour,  though  by 
constant  working  and  the  addition  of  a  very  little 
water  this  first  set  can  be  retarded  for  several  hours 
with  little  if  any  loss  in  the  quality  of  the  cement. 
13 


Nature  of  Mortar.  ^ 

Mortar  must  be  capable  of  plasticity  to  admit  its 
manipulation.  It  must  be  constant  in  volume — wet 
or  dry.  Must  possess  adhesion  and  cohesion;  must 
have  tensile  and  compressive  strength;  must  be  in- 
variable under  different  temperatures,  and  must  not 
be  affected  by  climatic  conditions. 

A  part  of  the  water  applied  to  mortar  when  mix- 
ing forms  with  the  solids  chemical  combinations, 
this  is  all  the  water  the  mortar  would  require  to  do 
its  best  work,  but  more  must  be  added  to  work  the 
mortar  plastic  for  use,  this  surplus  evaporates  again 
during  hydration.  Hence  too  lavish  use  of  water 
renders  mortars  porous,  as  parts  of  the  water  re- 
main suspended  in  the  mass,  causing  pock  marks,  etc. 

Freshly  mixed  mortars  present  the  following  ap- 
pearance in  succession: 

The  water  will  come  to  the  top  or  surface;  next 
this  water  will  be  absorbed  by  the  cement  and  evapo- 
ration. The  mortar  now  begins  to  heat,  and  lastly  re- 
turns to  its  normal  condition.  This  last  stage  is 
called  the  "first  set."  This  is  a  physical  and  chemi- 
cal process  and  at  this  stage  should  not  be  disturbed. 
Quick  setting  cements  arrive  at  this  point  in  about 
one-half  hour;  slow  setting  cements  in  about  two 
hours. 

This  "set"  is  on  when  the  surface  resists  a  slight 
pressure  of  the  finger  nails. 

Cement  once  set  is  capable  of  hardening  in  water 
or  air,  but  if  in  the  air  it  should  be  kept  wet  for 
6  or  8  days;  this  is  called  "seasoning." 

Mortar  in  a  short  time  acquires  a  high  degree  of 
strength.  "Setting"  and  hardening  of  cement  mor- 
tar should  not  be  confused,  they  are  not  the  same 
thing.  Hardening  begins  where  setting  leaves  off, 
and  then  continues  to  the  highest  strength  of  which 
the  cement  is  capable,  which  is  attained  only  after 
many  years.  Tests  have  shown  it  to  continue  for 
8  or  10  years. 

Quick  and  slow  setting  cements  may  impress  the 
inexperienced  workman  as  representating  quality  in 
favor  of  the  quick  cement.  This,  however,  is  not  the 
14 


case.  Cements  are  manufactured  in  their  chemical 
composition  to  be  either  quick  or  slow  setting  to 
meet  the  requirements  of  use.  Most  Portland  ce- 
ments are  slow  setting  as  these  are  best  adapted  to 
most  work.  Sometimes  in  submerged  work  a  quick 
set  is  desirable,  also  in  cast  work. 

Tests  show  that  initial  activity  is  frequently  ac- 
complished at  the  expense  of  gradual  increase  in 
hardness,  and  that  slow  setting  cements  have  grad- 
ually gained  and  overtaken  after  a  time  the  quick 
setting  varieties.  At  this  point  a  question  will  sug- 
gest itself.  Can  mortar  when  once  set  be  again  re- 
worked by  the  addition  of  water  and  safely  used? 
In  answer  to  this  question  we  can  name  no  more 
competent  authority  than  S.  B.  Newberry,  who  says, 
"That  it  should  not  be  again  used,  but  should  be 
cleaned  from  mortar  box  and  boards  and  thrown 
away,  and  not  again  incorporated  into  a  new  bed 
of  mortar,  as  is  frequently  done."  Another  writer 
of  considerable  practice,  Adolf  Cluss,  says,  "That  for 
a  day,  or  so  long  as  the  water  has  not  all  been  evapo- 
rated or  absorbed  the  bad  effects  may  be  mostly 
overcome  by  adding  a  minimum  of  water,  and 
beating  into  plasticity,  when  a  mortar  with  less 
hydraulic  activity  but  of  strong  and  sure  increase 
of  density  will  result."  In  fairness  to  both  authors 
there  might  be  too  much  play  on  the  word  "set." 
Much  would  depend  upon  the  stage  which  the  set 
had  attained.  Experiments  are  shown  to  corrobo- 
rate the  remix  statement.  Yet  the  practice  must  be 
admitted  as  dangerous,  and  should  be  discouraged. 
It  is  only  too  common  in  practice  as  workmen  know 
— to  rework  mortar  by  the  addition  of  water  until 
all  is  used.  Care  should  therefore  be  taken  to  mix 
up  only  such  a  quantity  of  mortar  as  can  be  con- 
veniently used  in  the  time  available. 

The  surface  of  stone  or  brick  to  be  bedded  in 
mortar,  also  surfaces  to  be  plastered,  should  be 
made  wet  before  mortar  is  applied  as  only  in  this 
way  can  cement  form  contact  or  adhesion  to  sur- 
face, an  important  requisite  in  good  work.  The 
seasoning  of  cement  work  24  hours  after  it  is 
15 


formed,  and  continuing  for  from  6  to  8  days,  must 
not  be  neglected.  Shade  from  hot  sun  and  currents 
of  air  by  covering  over  with  cut  grass,  straw  shav- 
ings, canvas  or  paper,  or  whatever  is  most  conven- 
ient and  will  not  discolor  the  work.  Upon  the  top 
of  this  if  porous,  sprinkle  water  thoroughly  each 
day.  If  covered  with  something  that  will  not  hold 
moisture,  or  that  you  do  not  wish  to  wet,  remove, 
sprinkle  and  again  cover.  In  cold  or  wet  weather 
this  is  not  important;  cellars  and  basements  need 
only  sprinkling.  Mortar  used  in  bedding  stone  or 
brick  is  not  usually  treated  in  this  way.  But  where 
they  are  kept  wet  for  several  days  following  the 
work,  much  is  added  to  its  strength  and  quality. 

Where  work  is  done  in  freezing  weather  the  mor- 
tar must  be  worked  with  as  little  water  as  possible; 
the  work  must  then  be  protected  by  covering  until 
thoroughly  set,  which  at  near  a  freezing  temperature 
may  be  for  several  days.  At  this  point  the  danger 
is  past  and  though  freezing  solid  after  this  the 
hardening  process  is  carried  unimpaired  until  such 
a  time  when  the  temperature  is  favorable  to  its 
ultimate  completion.  This  is  not  applicable  to  nat- 
ural cement  mortar.  Salt  is  frequently  used  in 
freezing  weather,  but  is  objected  to  by  many  as 
being  liable  to  impair  the  work,  also  discoloring 
same  by  white  incrustations. 

In  conclusion  on  this  subject  I  will  quote  from 
S.  B.  Newberry,  who  says,  "That  if  one  is  careful 
not  to  allow  any  free  water  to  separate  out  of  the 
mortar  and  become  absorbed  by  the  dry  surface  of 
stone,  brick  or  aggregate  used  there  is  scarcely  any- 
thing to  be  feared  from  the  action  of  heavy  freez- 
ing, and  when  compelled  to  do  cement  work  in  freez- 
ing weather  it  is  preferable  to  heat  the  water  and 
sand,  so  as  to  accelerate  the  setting." 

Cement  Mortar  can  be  used  during  the  hottest 
weather  of  the  season  without  any  bad  effect,  only 
that  great  care  must  be  taken  in  the  seasoning.  Sea- 
soned cement  is  the  greatest  heat  resisting  material 
known  to  the  building  trade,  while  this  had  often 
been  demonstrated  in  Europe  and  this  country  by 
16 


actual  tests,  it  remained  for  the  Baltimore  fire  to 
give  us  a  practical  illustration  of  its  real  merits, 
In  this  conflagration  of  the  7th  and  8th  of  February, 
1904,  which  continued  for  27  hours,  destroying  2,500 
buildings  and  producing  a  heat  of  3,000  degrees 
Fahrenheit,  when  granite  melted  like  lead,  the  steel 
skeleton  buildings  with  terra  cotta  fire-proofing 
failed  badly.  The  unequal  expansion  of  the  fire- 
proofing  and  the  steel  caused  the  terra  cotta  to  be- 
come detached  from  the  steel,  leaving  the  building 
after  the  fire  a  distorted  mass  of  iron,  while  the 
steel  skeletons  with  concrete  fireproofing  stood  the 
heat  with  little  or  no  damage.  Experts  who  visited 
the  burnt  district  agreed  that  no  building  withstood 
the  fire  better  than  the  Junker's  Hotel  and  the  In- 
ternational Bank  Building,  built  entirely  of  rein- 
forced concrete,  under  the  supervision  of  Messrs. 
Parker  and  Thomas,  architects,  of  Baltimore.  The 
heat  around  these  buildings  was  so  intense  that 
even  the  brick  which  elsewhere  held  out  were  en- 
tirely destroyed. 

Kinds. 

For  convenience  in  treatment  we  have  divided 
cement  mortars  into  four  classes,  namely:  Neat 
Mortar,  Portland  Cement  Mortar,  Natural  Cement 
Mortar,  and  Cement  Lime  Mortar.  We  can  treat 
on  these  only  briefly. 

Neat  Mortar  is  composed  of  cement  alone  mixed 
into  a  paste  by  the  addition  of  sufficient  water  to 
form  a  stiff  mortar.  This  mortar  attains  high  ten- 
sile strength  in  from  1  to  28  days,  after  which  fur- 
ther development  is  slow.  It  is  not  used  in  build- 
ing construction,  but  from  it  are  made  briquets  for 
experimental  use  in  testing  cement. 

Portland  Mortar  is  composed  of  Portland  Cement 
and  sand,  with  enough  water  to  work  plastic  for 
use.  The  proportion  of  sand  varies  with  the  differ- 
ent uses,  but  may  be  from  1  to  5  times  the  bulk  of 
cement.  This  mortar  stands  at  the  head  of  all  mor- 
tars in  building  construction,  is  reliable  in  all  cli- 
mates and  invariable  in  bulk. 

Natural  Cement   Mortar — Perhaps  better  known 
17 


in  many  localities  as  common  cement  mortar.  This  is 
composed  of  natural  cement  and  sand  with  water 
for  mixing  plastic.  This  cement  carries  less  sand 
than  the  Portland  and  can  be  used  only  with  safety 
with  from  1  to  3  times  its  bulk  of  sand.  This  mor- 
tar is  not  so  uniform  as  the  Portland,  frequently 
showing  slight  changes  in  volume,  is  affected  by 
e"matic  conditions;  is  used  mostly  in  massive  foun- 
dations, concretes,  cellar  bottoms,  and  cisterns,  and 
as  an  adjunct  in  lime  mortar. 

Cement  Lime  Mortar — This  is  composed  of  white 
lime,  1  part;  cement  (either  Portland  or  Natural), 
1  part,  and  sand,  1  to  7  parts.  This  mortar  is  not 
considered  hydraulic,  shows  slight  variation  in  vol- 
ume, is  very  plastic,  has  considerable  adhesive 
power,  can  be  used  wherever  white  lime  mortar  can 
be  used,  works  smooth  and  easily  with  trowel  and  is 
slow  to  set,  unexcelled  in  bonding  stone  or  brick  in 
ordinary  walling. 

PART  III. 

CONCRETES 

The  great  bulk  of  cements  the  world  over  are 
used  under  this  head.  Concrete,  as  the  word  implies, 
is  a  compound  or  aggregation  of  foreign  bodies  into 
one  mass.  Composition. 

Concrete  is  composed  of  cement,  sand  and  aggre- 
gate; this  aggregate  may  be  either  crushed  stone, 
gravel,  slag,  shells  or  cinders.  In  some  localities 
one  of  these  aggregates  is  most  convenient  and  is 
used,  and  in  other  localities,  others. 

Widely  varying  proportions  are  used  for  mixing 
concrete  in  general  practice,  and  in  many  cases  the 
quantities  are  gauged  in  so  crude  a  manner  as  to 
result  in  a  waste  of  material  and  indifferent  con- 
crete. 

This  aggregate  for  most  purposes  should  range 
in  size  from  %  to  2  inches,  the  more  variation  in 
size  and  shape  in  the  aggregate  used,  the  more  in 
bulk  can  be  incorporated  into  the  same  amount  of 
cement.  The  aggregate  used  must  be  hard,  with 
clean  surface  for  attachment.  The  sand  as  in  mor- 

18 


tar  for  quality  of  work  must  be  clean  and  sharp,  and 
for  economy  in  work  should  be  fine  and  coarse  mixed. 
It  is  very  difficult  to  lay  down  fast  rules  for  mixing 
concrete  with  so  wide  a  difference  in  the  aggregate 
and  sand  to  be  used.  It  is,  therefore,  important  that 
the  proper  proportion  in  each  case  of  sufficient  size 
should  be  ascertained  in  order  to  secure  the  best 
results  with  reasonable  economy.  This  is  easily 
done  by  filling  a  vessel  of  known  capacity  even  full 
with  the  aggregate  and  sand  mixed  in  the  propor- 
tion wished  for  use.  This  must,  however,  be  first 
thoroughly  soaked  so  as  to  absorb  no  more  water. 
Now  pour  in  as  much  water  as  the  vessel  will  con- 
tain and  divide  the  volume  of  the  water  poured  in 
by  the  volume  of  the  vessel;  the  quotient  will  repre- 
sent the  proportion  of  voids.  Or  to  more  fully  illus- 
trate, say  the  vessel  contains  4  gallons,  and  that 
after  being  filled  it  would  still  contain  V2  gallon  of 
water,  then  %-M/l  =  %X  lA  =  y»t  answer;  or  that  in 
8  volumes  there  are  7  sand  and  aggregate  and  1 
cement.  In  the  same  way  find  the  proper  proportion 
of  sand  to  use  with  the  aggregate,  and  cement  with 
sand. 

It  is  usually  customary  to  add  10  per  cent  for 
coating  over  the  particles,  but  when  this  is  properly 
rammed  into  place  as  concrete,  the  voids  are  suffi- 
ciently reduced  to  allow  enough  cement  for  coating. 

We  attach  so  much  importance  to  the  true  ratio 
of  these  component  parts  as  a  matter  of  economy 
and  quality  in  concrete,  that  we  venture  still  another 
method  that  may  assist  us  in  forming  proper  con- 
clusions as  to  proportions  of  cement,  sand  and  aggre- 
gate. 

It  is  a  mathematical  fact  that  if  sphere  (round 
bodies)  of  equal  size  were  placed  into  a  measure 
their  solids  would  equal  %  of  the  size  of  the  meas- 
ure and  the  spaces  or  voids  would  equal  %.  If 
these  spheres  were  aggregate  of  such  even  size  and 
shape  then  we  could  still  put  into  this  measure,  say 
of  6  gallons  2  gallons  of  sand  and  considering  the 
sand  to  consist  of  equal  sized  and  shaped  spheres, 
then  the  voids  in  the  sand  would  require  Va  of  2 
19 


'gallons  or  %  gallons  cement;  to  this  we  will  'idd 
for  the*  surf  ace  coating,  1/10  of  %  of  6  gallons,  or 
6/30=V5  gallon;  %X%  gallon  =  13/15,  about  %  gal- 
lon of  cement.  This  would  make  the  proper  propor- 
tions for  6  gallons  concrete  as  follows:  Aggregate, 
6  parts;  sand,  2  parts,  and  cement,  %  part.  But 
since  this  would  not  occur  that  all  the  particles 
would  be  equal  spheres,  we  can  readily  see  almost 
any  chance  lot  of  aggregate  would  be  more  favor- 
ably shaped  and  of  more  promiscuous  sizes  which  it 
will  be  seen  would  still  more  diminish  the  propor- 
tion of  cement.  Though  i;  must  be  remembered 
that  where  much  sand  and  less  aggregate  is  used, 
while  not  necessarily  increasing  the  voids,  the  sur- 
face coating  is  largely  increased.  The  sand  as  well 
as  the  aggregate  should  range  from  fine  to  very 
coarse.  We  will  give  two  formulas. 

Formula  No.  1. — Cement,  1  part;  sand,  2  parts; 
aggregate,  4  parts.  This  concrete  will  be  sufficiently 
strong  for  the  most  exacting  use. 

The  seven  volumes  of  this  formula,  when  thor- 
oughly tamped  into  place  would  fill  4%  or  5  volumes, 
showing  from  2  to  2V2  volumes  had  filled  into  inter- 
stices or  voids  of  the  mass. 

Formula  No.  2. — Cement,  1  part;  sand,  3  parts, 
and  aggregate,  6  parts.  This  concrete  is  used  for 
most  purposes,  and  could  still  be  weakened  to  sand, 
4  parts,  and  aggregate,  8  parts,  for  foundations  and 
heavy  body  work. 

The  10  volumes  of  this  formula  when  tamped 
into  place  will  fill  G1/^  or  7  volumes:  Mixing  and 
Handling — On  large  work,  machine  mixers  are  used. 
They  consist  of  a  rotary  cylinder,  into  one  end  of 
which  the  proportions  are  regularly  shoveled,  auto- 
matically sprinkled  and  mixed,  dropping  from  the 
other  end  of  cylinder  into  wheel-barrow  or  other 
receptacle,  ready  for  use.  This  is  a  very  expeditious 
and  also  a  very  thorough  way  of  mixing  concrete. 

But  much  of  the  work  for  some  time  to  come  will 
still  be  mixed  by  the  shoveling  process.  The  prep- 
aration for  mixing  should  always  depend  on  the 
magnitude  of  the  work  to  be  performed.  But  for  an 


ordinary  job  prepare  as  follows:  Prepare  mixing 
flour  of  surfaced  boards  laid  close  and  solid.*  and 
should  be  nearly  level,  this  should  be  large  enough 
that  the  mixing  need  not  be  hampered  for  want  of 
room,  say  8  x  12  feet.  It  should  be  placed  convenient 
to  materials  and  water,  from  which  point  when 
mixed  it  is  carted  or  carried  to  the  place  where  used. 

This  completed,  we  must  have  measures  by  which 
to  gauge  our  proportions  of  materials.  For  sake  of 
definite  illustration  we  will  use  Formula  No.  1.  In 
using  1  sack  of  cement  for  the  unit  (one  sack  con- 
tains about  1,900  cubic  inches),  then  our  sand  meas- 
ure should  contain  1,900x2  =  3,800  cubic  inches;  this 
box  has  no  bottom,  only  sides  and  ends  with  strips 
nailed  on  two  opposite  sides  for  handles,  and  while 
the  box  in  this  case  must  contain  3,800  cubic  inches, 
it  can  have  any  shape  desired,  say  18"  x  24",  or  432 
cubic  inches.  Fill  the  surface  one  inch  high,  then 
3,800^432  =  9  inches,  about  the  height  of  this  box 
inside  measure. 

This  same  measure  would  also  do  for  the  aggre- 
gate by  using  it  twice  full,  but  if  desired  another 
can  be  made  for  the  aggregate  in  the  same  way 
only  containing  twice  as  much  or  4  volumes. 

Place  sand  measure  near  one  end  of  the  plat- 
form and  fill  even  full  of  sand,  take  hold  of  handle, 
lift  and  allow  sand  to  spread  on  platform,  on  top 
of  this  empty  one  sack  of  cement;  next  measure  4 
volumes  of  the  aggregate  on  the  other  end  of  plat- 
form; spread  this  out  some  and  shovel  the  cement 
and  sand  over  onto  it,  taking  pains  in  the  shoveling 
to  mix  the  sand  and  cement  somewhat  evenly  on  the 
aggregate;  shovel  back  and  forth  until  the  whole  is 
evenly  mixed,  perhaps  about  2  times  if  carefully 
done;  now  with  spray  nozzle  and  hose  attached  to 
hydrant,  or  with  good  sprinkling  can,  one  man  will 
sprinkle,  watching  to  catch  the  dry  surfaces  while 
two  men  shovel  back  and  forth  2  or  3  times  or  until 
the  whole  mass  is  alike  mixed  and  wet.  It  is  wet 
enough  when  it  has  the  appearance  of  freshly  dug 
earth,  or  when  it  will  retain  its  shape  when  pressed 
in  the  closed  hand.  If  it  has  been  well  mixed  eveiy 
21 


particle  of  the  aggregate  will  be  evenly  coated  with 
the  cement  and  sand.  If  some  parts  have  been  made 
too  wet  the  surface  will  have  been  washed  clean, 
which  is  faulty.  We  should  have  stated  that  in  dry 
weather  the  aggregate  should  be  kept  moist  by 
sprinkling  while  on  the  pile  and  always  before  the 
sand  and  cement  are  shoveled  on  it.  This  is  im- 
portant as  the  cement  and  sand  will  stick  to  the  sur- 
face and  cover  more  easily  than  when  dry.  The 
concrete  is  now  ready  to  be  placed  where  used.  If 
near  enough  it  may  be  shoveled  into  place,  but  must 
not  be  thrown  a  distance  with  the  shovels  or  dumped 
into  deep  excavations,  because  in  doing  so  the  coarse 
and  fine  particles  separate  and  destroy  the  uniform 
density  and  quality  of  the  work.  To  illustrate,  sup- 
pose you  throw  a  shovelful  of  this  evenly  mixed 
concrete  12  or  16  feet,  as  is  sometimes  done,  and  it 
will  be  seen  that  on  leaving  the  shovel  the  fine  and 
coarse  particles  will  separate,  the  fine  and  richer 
part  will  lay  in  mass  where  it  falls  while  the  coarse 
particles  will  bound  and  roll  away  to  some  lower 
place  in  trench,  thus  practically  destroying  what  we 
had  taken  so  much  care  to  accomplish.  For  this 
reason  it  should  be  laid  or  thrown  at  a  short  range 
with  the  shovel  or  tipped  into  position  from  the  cart, 
evened  with  shovel  or  hoe  and  no  more  than  4  or  6 
inches  in  depth  placed  at  one  time  until  thoroughly 
rammed  with  iron  tamper  suited  for  this  work.  For 
a  small  job  a  wooden  tamper  could  be  made.  Take 
wooden  block  6  x  6  inches  square  with  hole  bored 
into  the  middle,  in  this  place  handle.  When  this 
layer  is  tamped  sufficiently  hard  and  even,  water 
will  slightly  appear  on  the  surface  which  indicates 
that  the  particles  are  driven  into  the  voids,  thus 
becoming  dense  and  driving  the  water  to  the  sur- 
face. If  the  concrete  in  tamping  should  quake  this 
will  indicate  that  it  is  too  wet.  The  additional 
layers  should  now  follow  in  the  same  way  as  the 
first  and  at  short  intervals  or  before  the  surface 
of  any  layer  dries  or  sets.  This  is  continued  until 
the  desired  height  is  reached.  If  the  surface  should 
at  any  time  become  dry  and  hard  before  completed 
22 


as  might  occur  during  night,  then  sprinkle  with 
water  and  with  fine  sieve  dust  cement  evenly  and 
lightly  over  the  surface.  This  will  give  a  new  base 
for  adhesion.  In  light  walks  and  floors  the  height 
is  built  up  at  one  application  of  concrete. 

The    setting   of   concrete    does    not   differ   much 
from  Mortar  (which  see),  only  that  the  aggregate 
acts  to  liquidate  the  heat  incident  to  chemical  action, 
thus  slightly  retarding  the  hardening  process. 
Nature. 

The  quality  of  concrete,  like  mortar,  will  depend 
upon  adhesion,  cohesion,  compressive  and  tensile 
strength,  and  invariableness  in  bulk.  These  are  at- 
tained by  the  irregular  bonding  or  the  interlocking 
of  the  coarser  fragments,  and  upon  the  strength  of 
each  ingredient  in  the  compound.  The  mass  must 
be  as  dense  and  homogeneous  as  possible. 

Enough  cement  is  required  to  form  a  coherent 
film  or  matrix  between  the  particles  which  by  inter- 
lacements consequent  upon  tamping  approach  each 
other  in  numerous  points  and  surfaces,  which  fol- 
lowing crystalization  of  the  cement  in  hardening 
becomes  a  dense  mass. 

In  the  combination  of  ingredients  for  concrete 
judgment  must  be  used  in  the  selection  of  sand  and 
aggregate  so  that  the  voids  in  the  aggregate  will  be 
thoroughly  filled. 

By  a  judicious  variation  in  the  size  of  the  aggre- 
gate as  well  as  the  particles  of  sand,  there  might 
often  be  built  twice  the  bulk  of  concrete  with  the 
same  amount  of  cement  without  any  sacrifice  in 
quality.  The  cement  must  fill  the  voids  in  the  sand, 
this  in  turn  must  fill  the  voids  in  the  aggregate. 
Concretes  must  not  be  prepared  before  they  can  at 
once  be  used,  as  they  can  under  no  condition  be  re- 
worked, and  when  set  before  placed  are  worthless. 

For  practice  the  following  conclusions  are  then 
arrived  at:  A  concrete  properly  proportioned  has  as 
much  strength  as  the  mortar  used  in  mixing  it.  By 
diminishing  the  aggregate  below  the  calculated  quan- 
tity, the  cost  of  the  concrete  is  increased  without 
benefit  to  its  strength.  Aggregate  that  is  rain 
28 


soaked  to  the  extent  that  it  is  dripping  wet  should 
not  be  used  until  the  water  is  slightly  evaporated. 
Also  aggregate  hot  and  dry  and  with  dusty  surface 
must  be  watered  sufficiently  to  make  it  moist. 

It  should  be  remembered  that  concrete  for  air  or 
submerged  work  differ  in  their  composition.  Air 
concrete  does  not  necessarily  need  be  so  dense  as 
submerged,  or  water  concrete.  We  herewith  give 
two  formulas  for  concrete  for  air  and  water  use. 
They  would  apply  to  ordinary  work: 

Formula  No.  1. — Air  Concrete — Cement,  1;  sand, 
2;  aggregate,  6  parts.  This  formula  consists  of  9 
volumes,  when  tamped  in  place  will  fill  6  volumes, 
and  would  weigh  green  approximately  150  pounds 
per  cubic  foot,  when  seasoned,  130  pounds. 

Formula  No.  2. — Water  Concrete — Cement,  1; 
sand,  3;  aggregate,  3  parts.  This  formula  consists 
of  7  volumes,  but  when  placed  and  tamped  dense 
will  fill  only  4  volumes,  and  when  green  would  weigh 
approximately  160  pounds  per  cubic  foot,  when  sea- 
soned, 145  pounds. 

Thus  while  slight  porosity  does  not  harm  air 
concrete,  for  submerged  work  it  must  be  dense  and 
impervious  to  water.  We  speak  of  invariableness 
in  volume  as  a  requisite  for  building  material. 
Strictly  speaking,  this  does  not  exist.  All  materials 
change  slightly  from  climatic  conditions,  such  as 
temperature  and  moisture.  But  we  do  claim  that  in 
concrete  it  is  reduced  to  the  minimum. 
Kinds. 

For  convenience  in  treatment  as  well  as  for  refer- 
ence to  special  work  by  the  reader,  we  have  classi- 
fied concrete  under  four  heads,  namely:  Ordinary 
Concrete,  Reinforced  or  Armored  Concrete,  Liquid 
Concrete,  Mortar  Concrete  and  Pulp  Concrete. 

Ordinary  Concrete  is  composed  of  cement,  sand 
and  aggregate,  mixed  as  specified  under  Concrete 
Mixing,  which  see.  When  mixed  it  is  rammed  into 
excavations  or  molds  prepared  for  its  use.  This 
form  of  concrete  is  perhaps  most  generally  and 
widely  used  for  massive  foundations,  walls,  piers, 
retaining  walls,  cellar  and  barn  walls,  walks  and 
24 


drives,  building  blocks,  and  other  cast  masonry, 
dams,  dykes,  and  many  government  and  railroad 
structures.  For  further  particulars  see  Part  4.  * 

Reinforced  or  Armored  Concrete  is  concrete  used 
in  every  way  as  under  Ordinary  Concrete  only  that 
in  addition  it  is  strengthened  by  iron  rods,  expanded 
metal,  wire  netting,  steel  beams  and  columns,  etc., 
imbedded  in  the  concrete.  This  serves  to  lessen  the 
bulk  of  concrete  used,  hence  an  economy  in  the  most 
difficult  construction  with  the  great  additional 
strength  secured.  It  also  makes  concrete  more  elas- 
tic so  essential  in  floors,  beams,  joist,  etc.  The  con- 
crete which  is  to  be  placed  about  this  metal  should 
be  slightly  wetter  than  for  ordinary  use  so  that  it 
can  be  puddled  about  the  motal  close  and  dense. 
Formerly  it  was  thought  necessary  that  metal  in- 
corporated in  concrete  should  first  be  well  painted, 
and  in  some  of  the  more  important  work  this  was 
even  wrapped  with  a  preparation  of  paper  to  pre- 
vent dampness  from  the  concrete  coming  in  contact 
with  the  metal,  also  prevent  chafing  in  tamping 
the  concrete.  But  extensive  and  elaborate  tests 
along  this  line,  recently  made  by  Professor  Norton, 
of  the  Massachusetts  Institute  of  Technology,  and 
other  experts,  it  has  been  clearly  established  that 
paint  and  paper  are  objectionable,  and  that  dense 
concrete,  with  contact  to  the  metal,  is  in  itself  the 
best  rust-proofing.  It  is  also  showed  that  slight  cor- 
rosion of  the  surface  of  metal  was  favorable  to  prop- 
er adhesion.  This  adhesion  is  claimed  to  be  equal  to 
from  500  to  700  Ibs.  per  square  inch,  and  to  form  an 
air-tight  covering.  Its  grip  on  the  surface  of  the 
metal  prevents  shearing  by  elongated  strength, 
which  in  the  case  of  covering  by  paint  or  paper  would 
be  lost.  Formerly  it  was  thought,  too,  that  the  ex- 
pansion and  contraction  of  concrete  and  metal  would 
be  so  unequal  that  adhesion  was  not  even  desired, 
but  it  js  now  known  that  they  are  the  same  and  can 
be  relied  on,  as  was  amply  shown  in  the  Baltimore 
conflagration,  where  the  expansion  incident  to  the 
great  heat,  showed  no  signs  of  ruptured  cohesion  of 
metal  and  concrete,  while  terra  cotta  on  account  of 
25 


its  rapid  expansion  buckled  and  broke  its  bonding  on 
the  metal.  In  this  limited  space  we  cannot  give  de- 
tails for  placing  this  metal  in  the  various  construc- 
tions. This  will  be  the  work  of  the  engineer,  and  it 
will  be  enough  to  say  that  it  must  be  so  placed  that 
it  will  give  the  greatest  support  to  the  concrete.*  It 
should  be  entirely  enclosed  in  the  body  of  the  con- 
crete and  be  near  the  opposite  side  from  the  pres- 
sure. Where  possible  should  be  placed  so  as  "to 
truss  and  equalize  strains. 

It  is  found  that  by  the  incorporation  of  metal 
in  concrete,  reasonable  size  can  be  easily  maintained 
with  ample  safety  in  strength.  And  while  the  plac- 
ing of  metal  for  reinforcing  requires  some  engineer- 
ing skill,  and  perhaps  properly  would  not  come  under 
the  scope  of  this  book. 

Yet  to  meet  the  great  demand  by  the  ordinary 
workman  lor  knowledge  governing  the  primary  prin- 
ciples in  common  construction,  we  venture  in  this 
revision,  a  few  brief  and  simple  directions  for  which 
the  engineer  will  excuse  the  terms  used  and  appli- 
cations made  in  this  talk  with  our  laboring  fellow 
craftsmen.  Perhaps  all  work  for  whatever  purpose 
constructed,  must  resist  stress.  Stress  is  force,  and 
to  designate  the  nature  of  stress,  we  will  use  the 
following  terms:  Compressive  stress,  crushing  force; 
tensile  stress,  pulling  apart  force;  tprsional  stress, 
twisting  force;  shearing  stress,  cutting  force. 

These  are  the  most  common  stresses  encountered 
in  construction. 

The  compressive  or  crushing  strength  of  con- 
crete is  its  greatest  strength  attainable,  and  is  ap- 
proximately ten  times  its  tensile  strength,  or  from 
2,000  to  4,000  Ibs.  per  square  inch.  About  the  most 
that  is  accomplished  in  the  best  methods  of  rein- 
forcing is  to  unify  other  stress  and  bring  them  up 
to  compressive  strength.  Walls,  columns  and  arches 
are  instances  of  compressive  stress.  Tensile  stress 
is  pulling  apart  or  tearing  force,  and  is  approxi- 
mately 200  ot  400  Ibs.  per  square  inch.  This  is 
easily  brought  up  to  the  compressive  stress  by  ten- 
sion rods.  The  lowei  side  of  beams  and  lintels,  and 
the  contraction  incident  to  cement  work,  represent 
26 


cases  of  tensile  or  tearing  stress. 

)  Torsional  stress,  or  wrenching  force  is  occasioned 
by  side  thrusts  on  wall  columns,  and  is  always  pres- 
ent in  beams.  Shearing  stress,  or  cutting  force,  is 
sometimes  occasioned  near  walls  or  columns,  in 
floors  or  beams,  at  times  by  reinforcing  rods  im- 
properly placed. 

Columns  bearing  up  a  perpendicular  weight 
rarely  need  reinforcing  with  metal,  but  where  they 
encounter  side  thrusts  or  extraordinary  weight  they 
are  reinforced  by  perpendicular  rods,  and  outside 
of  these  spiral  bands  these  are  placed  nearest  out- 
side shell  of  hollow  column  and  sufficiently  near 
each  other  to  prevent  buckling  of  concrete. 

Beams — short  beams,  lintels  and  caps  are  usually 
reinforced  by  a  few  tension  rods  near  lower  side. 
But  beams  and  lintels  carrying  weight  over  large 
openings  represent  the  most  difficult  methods  of 
reinforcing,  as  they  encounter  what  I  am  pleased 
to  call  compound  stress  compression  in  upper  middle, 
and  tensile  in  lower  middle  parts.  The  deflection  down- 
ward in  middle  causing  torsional  stress  near  the  end 
support  of  beam,  while  perpendicular  with  column 
or  wall  supporting  beam  shearing  stress  is  present. 

A  common  and  practical  method  of  reinforcing 
ordinary  beams  is  to  use  two  or  more  tension  rods, 
extending  length  of  beam,  parallel  with  and  near 
lower  surface  of  beam.  These  prevent  the  beam 
from  tearing  at  lower  center  and  from  shearing  at 
column  or  wall;  also  hold  lower  ends  of  beam  from 
crowding  endways  from  center,  thus  disturbing  the 
stress  in  the  form  of  a  sequent  arch,  having  the 
radius  of  height  of  beam.  The  beam  is  further  rein- 
forced by  two  or  more  truss  rods,  extending  from 
upper  ends  of  beam  to  the  lower  middle,  these  over- 
come the  deflection  at  center  or  torsional  stress.  These 
with  a  few  U-shaped  rods  looped  under  lateral  rods 
and  projecting  with  open  inverted  T-shaped  end 
near  the  upper  surface  of  beam  constitute  all  the 
reinforcing  necessary  for  most  ordinary  work.  The 
size  of  rods  or  bars  used,  as  well  as  size  of  beam, 
must  be  determined  by  length  of  span  and  weight  of 
load  to  be  supported. 

27 


general  principles  of  reinforcing  are  agreed 
on  by  all  engineers,  but  as  to  methods  used  in  detail 
all  do  not  concur.  Some  use  round  rods,  some 
square  rods,  others  use  twisted  square  rods,  some 
corrugated  rods,  others  still  use  such  devices  as  the 
Kahn  system — heavy  sheet  metal,  with  ribs  pro- 
jecting at  various  angles  into  the  body  of  beam 
above.  When  engineers  do  not  agree  we  certainly 
do  not  venture  an  opinion,  any  more  than  to  say: 
That  personally  with  the  most  careful  work  in  pre- 
paring and  puddling  concrete  around  the  rods,  there 
might  not  be  much  difference  in  ultimate  strength; 
but  that  where  this  work  is  done  with  less  care,  ad- 
hesion to  surface  of  metal  is  often  imperfect,  often 
the  metal  being  jarred  loose  in  concrete,  in  such 
cases  losing  elongated  strength,  where,  in  twisted, 
corrugated  or  ribbed  rods  or  bars,  though  imperfect 
adhesion  existed,  the  rods  would  still  be  held  from 
slipping  in  the  concrete  sheath. 

Before  rods  are  placed  in  beams  or  lintels  cen- 
tering or  the  building  of  forms  is  completed,  these 
require  skill  in  their  construction,  and  in  face  work 
requiring  mouldings  and  panels.  The  molds  must 
be  thoroughly  expanded  6  to  10  hours  before  con- 
crete is  placed  in  them,  or  the  later  expansion  will 
replace  edges  of  raised  work  and  impair  it. 

Concrete  for  this  work  must  be  of  the  best  and 
most  suitable  materials  only.  Where  rods  are  many 
and  sometimes  space  between  them  small,  large  par- 
ticles in  concrete  must  be  avoided. 

The  concrete  for  this  work  must  be  wet  enough 
so  that  no  tamping  is  required,  instead,  puddle  with 
a  thin  stick  into  all  corners  and  between  bars,  jar- 
ring of  rods  in  this  semi-plastic  condition  helps  to 
adjust  the  concrete  to  the  surface,  but  this  must  be 
most  carefully  avoided  when  the  concrete  begins  to 
set.  We  would  not  recommend  using  liquid  con- 
crete. This  separates,  becomes  stratified  and  very 
unreliable;  also,  as  the  excess  of  water  is  forced  to 
the  top,  the  concrete  settles,  leaving  open  space 
along  bottom  of  rods.  Use  only  wet  enough  to  pud- 
dle. ^This  will  not  separate,  or  shrink  in  setting,  but 
will  become  dense  and  hard  as  adamant.  $ 

28 


r  The  introduction  of  this  method  of  concrete  has 
vastly  extended  the  use  of  cement  in  the  building 
trade,  not  only  in  this  country  but  as  well  in  for- 
eign lands.  Among  a  few  of  its  more  common  uses 
might  be  mentioned  floors,  roofs,  partitions,  ceil- 
ings, walls,  columns,  cornices,  bridges,  subways, 
reservoirs,  flumes,  vaults,  tanks,  dry  kilns,  dry  docks, 
houses,  factories,  etc. 

Liquid  Concrete — This  form  of  concrete,  much 
used  formerly,  is  still  indispensable  in  some  cases, 
though  it  is  objected  to  by  engineers  of  today  as 
being  unreliable.  Liquid  briquets  invariably  show 
lower  ratings.  It  is  claimed  that  by  the  excessive 
use  of  water  the  cement  is  diluted,  that  aggregate 
placed  for  filling  is  often  "choked"  (clogged),  that 
the  particles  of  sand  separate  from  the  cement  in 
pouring,  destroying  uniformity  in  the  mass. 

While  these  objections  are  well  taken,  still  much 
may  be  overcome  by  the  careful  workman;  the  chok- 
ing entirely,  and  the  separation  of  sand  and  cement 
partly. 

It  is  necessary  to  use  fine  sand  in  order  to  avoid 
separaton;  this  will  cost  some  additional  cement 
for  surface  coating.  In  coarse  sand  the  fine  par- 
tirles  of  cement  will  float  with  the  water,  leaving 
the  heavy,  coarse  particles  in  the  bottom  of  mixing 
vessel,  or  in  pouring  will  settle  to  the  bottom,  leav- 
ing the  richer  part  (fine  particles  of  sand  and  ce- 
ment) floating  to  the  top.  Some  workmen  place  the 
aggregate  first  and  pour  the  voids.  Others  think 
a  safer  way  is  to  first  pour  the  liquid,  and  into  this 
place  the  aggregate  in  the  following  way:  A  tight 
box  or  mixing  vessel  is  made  suitable  in  size  to 
the  work  at  hand,  say  in  this  case  2  feet  high,  2  feet 
wide  and  6  feet  long,  with  strips  nailed  on  the  sides 
and  projecting  at  the  ends  for  handles  by  which  the 
box  may  be  quickly  turned  over  in  emptying  or 
carried  about  in  using. 

For  our  purpose  in  illustrating,  will  suppose  this 
construction  to  be  a  foundation  in  excavated  trench. 
Set  box  near  trench  so  that  when  ready  it  can  be 
turned  over  on  one  side  emptying  the  contents  into 
the  trench  without  lifting  or  carrying;  now  pour 
20 


into  the  box  4  pails  of  water,  and  with  a  man  at 
each  end  of  box  with  mixing  hoe;  put  into  box  1 
sack  of  cement.  While  this  is  being  stirred  vigor- 
ously, throw  in  4  times  as  much  sand;  when  stirred 
until  all  is  reduced  and  afloat,  turn  box  quickly  on 
side,  dumping  contents  into  the  trench.  Now  having 
aggregate  handy,  place  this  into  the  liquid  at  once, 
but  not  in  mass  so  as  to  choke;  when  this  is  filled 
proceed  as  before  until  the  height  is  reached.  Where 
trenches  are  large  only  a  part  must  be  treated  at 
one  time.  Whenever  it  is  thought  best  to  place  the 
aggregate  first  this  may  be  done.  Place  the  aggre- 
gate not  over  a  foot  in  height,  and  this  should  be 
sufficiently  coarse  so  that  the  liquid  may  fill  into 
all  the  voids;  pour  the  liquid  on  top  of  this,  until  it 
floats  over  the  top,  when  place  another  foot  of  aggre- 
gate on  top  and  continue  as  before,  to  the  desired 
height.  The  liquid  mortar  should  be  as  thin  as  gruel 
for  most  purposes,  and  the  proportion  of  fine  sand 
and  cement  may  be,  cement,  1  part,  and  sand,  2  to  5 
parts,  according  to  the  requirement  of  the  work. 
When  it  is  required  to  use  this  grout  or  liquid  in 
cast  masonry,  a  water-tight  form  is  prepared  into 
which  aggregate  can  be  placed,  or  the  cast  may  be 
entirely  of  liquid  mortar  as  desired. 

Another  place  where  this  liquid  mortar  is  used 
with  advantage  is  in  pouring  out  beds  and  joints  of 
massive  stone  in  foundations  and  walls.  When  these 
stone  blocks  are  laid  into  walls,  the  front  and  back 
bed  joints  are  spread  with  mortar;  into  this  the 
blocks  are  laid,  making  them  liquid-tight.  When 
the  course  is  thus  laid,  the  end  or  vertical  joints  of 
face  and  back  are  closed  with  mortar;  these  joints 
are  now  poured  full  of  liquid  mortar  until  the  bed 
and  end  joints  are  filled  even  with  top  of  course,  in 
this  way  filling  every  space  of  bed  and  end  joints. 

This  plan  of  work  is  highly  recommended  for  re- 
taining and  abutment  walls,  which  must  hold  great 
pressure  from  the  bank  crowding  and  shearing  the 
wall. 

It  is  the  opinion  of  a  practical  engineer  that  a 
wall  of  this  description  with  4-foot  bed  would  resist 
a  bank  pressure  equal  to  a  6-foot  bed  laid  up  in  the 
30 


ordinary   way.  j 

Heavy  walls  with  wide  beds  are  sometimes  built 
with  two  masonry  faces,  the  face  stone  sometimes 
for  bonding  extending  into  the  middle  or  across  the 
wall,  this  middle  is  filled  in  with  each  course  with 
waste  stone  from  face  dressing,  etc.,  then  poured  out 
with  liquid  cement.  This  method  of  work,  when 
care  is  taken  that  no  uneven  shrinkage  or  expan- 
sion occurs,  has  few  equals,  if  indeed  any.  In  this 
kind  of  work  only  Portland  cement  should  be  used, 
since  natural  cements  are  more  variable,  sometimes 
showing  expansion  and  destroying  the  bonding.  For 
this  work  the  cement  and  sand  are  mixed  dry  and 
placed  on  or  convenient  to  the  wall,  when  the  work- 
man with  a  large  pail  suited  to  this  work,  fills  the 
pail  %  full  of  water,  as  many  shovels  full  cement 
and  sand  mixed  as  will  make  it  when  mixed  about 
as  thick  as  a  thin  gruel;  before  mixing  in  the  pail, 
which  he  does  with  a  large  trowel,  he  takes  the  pail 
where  it  is  to  be  turned  into  the  joint;  stirs  it  vig- 
orously until  evenly  mixed  and  afloat,  when  it  is  at 
once  turned  into  the  joint.  If  not  turned  over  quick 
the  coarse  sand  settles  into  the  bottom  of  the  pail. 

Mortar  Concrete — In  this  concrete  the  cement  and 
sand  in  the  proportions  desired,  which  may  be  from 
1  to  6  parts  coarse  sand  to  1  part  cement,  are  mixed 
into  a  mortar  of  easy  working  plasticity,  into  which 
is  incorporated  the  aggregate,  which  may  be  quite 
coarse.  The  need  for  this  mortar  concrete  is  that 
for  aggregate,  coarser  materials  are  used  than  could 
well  be  used  in  ordinary  concrete;  the  surface  of  the 
aggregate  must  be  dampened  and  be  clean  in  order 
to  form  contact.  In  some  parts,  small  stone  rang- 
ing front  the  size  of  a  fist  to  6  or  8  inches  in  diam- 
eter are  abundant,  while  crushed  stone,  gravel,  and 
the  regular  aggregate  materials  are  scarce.  In  the 
mortar  concrete  these  can  be  used  advantageously, 
while  costing  slightly  more  in  cement  on  account  of 
the  large  voids,  the  handiness  of  the  stone  more  than 
overcome  this.  If  properly  constructed  little  or  no 
difference  in  the  quality  of  work  will  result.  The 
mortar  is  thrown  into  the  form  little  at  a  time  and 
the  stone  pressed  into  it,  shoving  the  stone  always 
31 


toward  the  surface  or  face  so  as  to  leave  it  even  and 
compact.  If  the  stones  are  shoved  down  into  the 
mortar  along  the  form  they  displace  the  mortar 
between  the  form  and  the  stone,  leaving  the  stone 
exposed  on  the  surface.  Some  care  should  also  be 
used  in  filling  the  voids  of  the  larger  stone  by 
smaller  ones,  etc.,  in  this  way  reducing  the  quantity 
or  mortar,  but  no  stone  should  be  placed  on  top  of 
others  dry.  The  mortar  must  form  an  unbroken 
matrix  throughout  the  mass. 

Pulp  Concrete — Is  composed  of  cement  sand  and 
wood  pulp  or  saw  dust.  The  matrix  is  composed  of 
the  cement  and  sand,  and  for  the  aggregate  pulp  is 
used  in  quantity  to  suit  the  use  for  which  it  is  in- 
tended. It  is  not  used  for  outdoor  work,  but  for  plas- 
tering, and  fireproofing  interior  wall,  veneering  floors, 
etc.  It  has  less  tensile  strength,  is  slightly  elastic  and 
much  lighter  in  weight  than  ordinary  concrete. 

It  is  especially  desirable  for  floor  veneering,  for 
market  houses,  butcher  shops,  saloons,  etc.,  though 
practically  non-absorbent,  is  slightly  elastic  and  the 
rigidness  for  foot  use,  common  in  ordinary  concrete 
is  overcome.  Lay  paper  over  floor,  on  this  spread 
concrete  to  thickness  of  l1/^  inches,  no  joints  are 
necessary,  it  will  not  check.  Mix  in  the  following 
proportions:  Cement,  1  part;  sand,  2  parts,  and 
pulp  or  fine  saw  dust,  2l/2  parts.  When  more  pulp 
is  incorporated  it  becomes  absorbent,  since  the  mat- 
rix will  be  broken,  finish  top  smooth. 

PART  IV. 

CAST  MASONRY 

Under  this  head  are  included  all  artificial  stone 
products,  cast  from  concrete  or  mortar. 

We  do  not  aim  to  exhaust  the  large  and  con- 
stantly growing  scope  of  these  useful  products,  in 
the  limits  of  this  treatise,  but  rather  it  is  our  pur- 
pose to  take  some  of  the  more  commonly  used  and 
to  give  such  general  directions  in  their  construction 
that  the  average  workman  may  with  some  origi- 
nality of  thought  and  purpose  apply  himself  to  more 
complicated  work  with  assurance  of  success.  Though 
32 


to  be  a  thorough  workman,  unhampered  and  re- 
sourceful, it  is  important  that  the  Parts  preceding 
this  on  Cement,  Mortar  and  Concrete?  should  be  care- 
fully read,  since  in  these  brief  directions  we  pre- 
sume our  reader  to  be  familiar  with  cement  and  its 
nature  in  mortar  and  concrete,  also  all  about  sand 
and  aggregate  and  their  mixing,  etc. 

For   pur  own   and   the   readers'   convenience   we 
will    divide    this    Part    into    two    sections,    namely: 
Monolithic  and  Portable  Cast  Products. 
Monolithic  Cast  Masonry. 

By  stationary  cast  masonry  we  mean  that  part 
of  masonry  which  is  built  on  the  spot  where  used, 
either  in  excavations  or  forms,  such  as  foundations, 
walls,  floors,  ceilings,  fire-proofing,  walks,  drives, 
steps,  cisterns,  reservoirs,  grave  vaults,  etc. 
Foundations  and  Footings. 

This  embraces  one  of  the  chief  uses  of  concrete. 
By  foundations  we  mean  bases  or  footings  for  walls. 
These  may  be  submerged  or  above  water.  Sub- 
merged concrete  is  in  some  rare  instances  laid 
directly  in  water.  In  such  cases  a  crib  is  built  in 
the  water,  marking  outline  of  the  concrete,  into  this 
the  concrete  is  deposited,  the  crib  holding  it  in  place 
until  it  has  hardened.  More  commonly  in  the  sub- 
merged work  the  space  is  inclosed  by  a  tight  crib 
or  cofferdam,  with  steam  pumps,  or  by  compressed 
air,  the  water  is  then  removed.  The  bottom  now  is 
excavated  to  a  secure  bed,  and  when  soft  and  yield- 
ing bottoms  are  encountered  for  a  considerable 
depth,  this  is  piled  sufficiently  until  the  engineer  is 
satisfied  that  it  will  sustain  the  strain  for  which  it 
is  intended.  Where  the  crib  does  not  form  the  out- 
line of  the  foundation  a  form  must  be  constructed, 
the  piling  is  usually  allowed  to  extend  from  bottom 
of  trench  into  the  concrete,  but  should  be  sawed  off 
below  low-water  mark.  Now  we  are  ready  to  place 
the  concrete:  this  submerged  concrete  may  consist 
of  cement,  1;  sand,  3;  aggregate,  3.  See  "Mixing 
Concrete"  for  mixing  method  of  mixing  and  tamp- 
ing. Where  area  of  surface  is  large,  it  is  best  to 
bring  up  only  a  part  at  a  time;  place  about  six 
inches  of  concrete  at  once;  even  with  hoe  or  shovel; 
33 


tamp  solid  and  even.  This  is  continued,  layer  after 
layer,  until  top  is  reached,  where  piled  the  tops  of 
the  piling  are  Jield  firmly  in  place  by  the  concrete 
tamped  densely  about  them,  and  finally  covering 
over  them  entirely.  This  more  evenly  adjusts  the 
weight  over  the  whole  surface  and  on  each  pile  than 
any  other  form  of  construction  could  possibly  do. 
When  the  work  is  from  24  to  36  hours  old  it  may  be 
submerged  with  benefit  to  the  work.  It  must  not 
be  forgotten  that  hydraulic  concrete  must  be  thor- 
oughly tamped  to  make  it  impervious  to  water.  This 
foundation  could  be  continued  in  the  same  way  its 
entire  height  if  desired,  only  requiring  forms  to 
shape  its  outline,  but  this  will  more  properly  be- 
long to  walls  of  which  we  will  speak  later.  Founda- 
tions are  so  varied  that  in  this  space  we  can  not 
cite  others,  only  to  say  that  the  work  can  easily  be 
adjusted  to  meet  any  requirements.  We  will  give 
another  illustration  of  a  foundation  or  footing  above 
water.  The  object  of  a  footing  is  to  distribute  the 
weight  or  bearing  of  a  heavy  wall  or  building  over 
a  greater  bearing  surface,  thus  preventing  settlings. 

Footings  for  buildings  must  project  from  either 
side  of  the  wall  the  same  distance,  and  the  thickness 
should  never  be  less  than  the  projection.  A  string 
is  stretched  true  to  line  of  footing,  from  this  the  ex- 
cavation is  made  sufficiently  exact  in  line  and  depth 
of  trench,  that  the  concrete  can  be  tamped  in  place, 
the  trench  serving  as  a  form.  If  the  ground  in- 
clines the  trench  must  not  follow  the  incline  but  be 
nearly  level,  and  to  meet  the  incline,  the  excavation 
should  drop  down  at  right  angles,  then  continue  again 
until  another  drop  is  necessary,  etc.  Soft  or  yield- 
ing places  in  the  bed  must  be  taken  out  in  the  same 
way,  not  scooped  out  but  blocked  out.  When  the 
excavation  is  completed  the  concrete  is  placed. 

Above  water  we  shall  use  air  concrete,  cement, 
1    part;    sand,    3    parts;    aggregate,    6    parjts.      See 
''Mixing  and  Placing"  of  concrete. 
Walls. 

These  of  whatever  nature  or  kind  may  be  built 
from  concrete  and  are  declared  by  the  engineers  of 
the  day  to  be  superior  to  any  other  method  of  con- 
^  34 


struction  in  vogue.  They  are  made  from  ordinary 
concrete  and  reinforced  concrete,  to  suit  require- 
ments. ,Walls  built  from  cast  blocks  (portable)  will 
be  treated  of  in  the  second  division  of  this  Part,  /but 
all  heavy  and  low  walls  can  be  built  up  by  contin- 
uous masonry  in  their  place,  using  suitable  forms 
or  molds.  These  forms  are  of  two  kinds  in  general 
use,  which  we  will  endeavor  to  describe  at  this  point. 

Box  Form — This  consists  of  a  plank  form  set 
true  with  the  face  line  in  the  same  way  as  a  stone  is 
laid  with  the  line,  these  are  carried  in  courses,  using 
some  care  with  the  first  course  to  get  the  top  level, 
the  form  is  set  on  top  of  this  course,  the  face  line 
raised  and  the  box  or  form  set  true  with  line  and 
plumb  with  face;  this  is  continued  to  the  top  course. 
This  must  be  kept  true  and  level  for  sill.  If  the 
forms  are  carefully  trued  each  time  the  wall  will 
have  full  and  even  faces,  and  is  by  most  mechanics 
preferred  to  a  plastered  face,  but  if  by  amateur 
workmen  the  wall  in  all  probabilities  must  be  plas- 
tered to  make  it  presentable.  It  is  best  to  have  two 
forms  and  to  work  them  alternately  on  different 
courses  or  on  different  parts  of  the  wall.  This  will 
give  time  for  slight  set  before  the  form  is  removed. 
Where  more  than  two  or  three  hands  are  employed 
on  the  work  more  forms  will  be  required.  If  it  is 
desired  to  have  the  wall  sloped  or  battered  towards 
the  top  this  can  readily  be  accomplished  by  adjust- 
ing the  box  for  this  purpose.  When  the  height  is 
reached  for  door  or  window  frames  to  be  set  they 
should  be  set  and  secured  in  position;  the  wall  can 
now  be  continued  over  them,  with  a  little  care  to 
batten  the  frames  (if  the  wall  is  wider  than  frame, 
which  it  should  be).  This  makes  a  nice,  true  and 
even  jamb:  a  narrow  strip  should  be  so  placed  on 
the  jambplanks  of  the  door  or  window  on  the  wall 
side,  so  that  the  wall  will  hold  it  in  position  when  set. 

For  the  box  secure  two  straight  and  true  planks, 
some  stiff  light  wood  is  preferable.  For  ordinary 
work  these  should  be  1  foot  wide  and  about  12  or  14 
feet  long.  Saw  these  off  square  at  one  end,  and  nail 
board  the  same  width  as  sides  across  ends,  making 
the  space  between  the  plank  to  correspond  to  the 
35 


width  of  wall.  Before  nailing  board  across  the  end 
referred  to,  it  is  best  to  take  square  and  mark  across 
the  board  for  the  inside  edge  of  each  plank.  In 
this  way  the  sides,  top  and  bottom  will  be  parallel 
and  at  right  angles.  It  is  best  if  the  board  projects 
by  the  outside  edges  of  the  plank  a  few  inches, 
forming  hand  hold.  Our  box  now  has  sides  and  one 
end  closed,  the  other  end  will  be  left  open;  turn  bot- 
tom side  of  box  up  and  about  12  inches  from  open 
end  saw  notch  in  lower  edge  of  side  plank  1% 
inches  deep  and  2  inches  wide  and  split  out;  repeat 
this  in  the  same  way  half  way  between  this  notch 
and  closed  end;  now  take  4  strips  1  foot  longer  than 
width  of  wall,  and  l1/^  inches  square,  into  these  saw 
notches  2%  inches  wide  and  half  the  depth  of  th° 
stick  %  inch,  and  BO  that  when  the  plank  is  agains. 
the  outer  edge  of  the  notch  the  space  between  the 
plank  will  be  the  exact  width  of  the  wall,  and  the 
same  at  each  end,  aHmro  and  below  i'he  box  is  now 
ready  for  use,  and  *>vm*,  care  is  required  that  it 
is  not  strained  out  of  shape  in  handling.  To  place 
the  form  in  position  for  the  first  stone  put  closed 
end  to  corner;  this  will  make  square  corner;  set  box 
on  two  strips  at  the  notches  and  clap  the  other  two 
strips  across  top  above  lower  ones;  now  true  box 
with  face  line,  and  with  level  set  plumb  and  level, 
fill  with  concrete  %  full  and  tamp,  fill  balance  and 
tamp  again  till  even  full;  now  set  the  other  box  in 
the  same  way  on  some  other  portion  of  the  wall; 
when  this  is  filled  remove  the  first  box  by  first  re- 
moving the  top  strips;  lift  sufficiently  at  the  open 
end  of  form  to  remove  from  notches;  now  spread 
the  open  end  6  inches  from  the  wall  on  each  side 
and  at  the  same  time  lifting  about  1  foot,  so  as  to 
throw  away  at  the  top  at  closed  end;  now  with 
another  man  at  the  closed  end  the  box  is  lifted  and 
at  the  same  time  pulled  slightly  toward  the  closed 
end,  to  avoid  breaking  the  green  block  thus  formed. 
Turning  the  box  end  for  end,  lap  the  open  end 
slightly  on  block  formed,  place  strips,  true  to  line 
as  before  and  continue  in  this  way.  In  some  cases 
the  sticks  can  not  be  used  below  on  the  bottom 
Bourse  on  account  of  not  being  able  to  remove  then: 
06 


for  bank,  etc.  In  this  case  support  the  box  foB 
this  course  at  the  bottom  in  some  other  way,  after 
this  they  can  be  used  every  time,  and  each  time 
when  the  box  is  removed  by  slightly  tapping  them 
with  the  hand  they  are  easily  pulled  from  the  wall 
and  placed  on  the  next  form.  This  can  be  contin- 
ued as  rapidly  as  desired.  Two  hours  after  any 
block  is  out  of  the  form,  or  2  hours  after  it  is  made 
.another  can  be  placed  on  top  as  before.  Three  men 
with  the  proper  materials  handy  will  lay  from  200 
to  300  cubic  feet  per  day.  Where  nice  work  is  de- 
sired some  care  must  be  taken  in  working  about  the 
green  blocks,  so  that  corners  are  not  chafed  off  or 
parts  broken.  If  plastered  this  will  not  matter,  but 
if  left  cast  finish  it  should  not  show  trowel  marks 
or  bruised  surfaces.  The  strip  holes  in  the  wall 
may  be  closed  at  any  time;  close  with  concrete  and 
rake  off  rough  with  trowel  and  they  will  not  show, 
but  if  closed  with  mortar  as  they  sometimes  are 
they  will  show  unless  plastered.  If  the  wall  is  plas- 
tered and  a  good  finish  is  desired,  when  the  plas- 
tering is  partly  set,  go  over  the  surface  with  stiff 
broom  or  wire  brush,  stroking  in  the  same  direction 
each  time,  or  for  rubbed  sand  stone  finish  rub  with 
wood  float,  trace  the  walls  into  blocks  with  jointer, 
after  sweeping  or  rubbing  but  before  dry.  This 
gives  it  a  pleasing  appearance. 

In  a  battered  wall  (narrow  at  the  top)  the  form 
must  be  changed  each  course  to  correspond  with  the 
battered  width  of  wall  for  each  course.  When  walls 
are  not  over  3  or  4  feet  high  and  less  than  18  inches 
wide  and  are  laid  in  lengths  of  over  16  or  20  feet, 
there  should  be  a  continuous  perpendicular  joint  to 
avoid  "settling  or  shrinkage  cracks."  In  still  lower 
and  lighter  walls  they  should  be  laid  in  6  or  8-foot 
lengths,  while  in  the  former  12  or  14-foot  lengths 
would  be  allowed  without  danger  of  checking,  but 
where  the  bottom  is  good,  heavier  walls  can  be  con- 
tinued to  great  lengths.  To  make  this  joint  insert 
heavy  metal,  slate,  or  surfaced  board  ^  inch  thick, 
at  the  proper  place  in  the  form;  tamp  well  on  each 
side  and  before  the  form  is  removed,  take  hold  of 
the  top  projecting  above  the  form,  move  slightly 
37 


until  loose  and  then  remove;  insert  the  next  divider 
directly  above  this  and  so  on. 

When  the  work  is  two  or  three  days  old  point 
this  joint  as  you  would  a  stone  joint  with  mortar. 
When  this  wall  is  24  or  36  Lours  old  it  must  be 
sprinkled  once  or  twice  each  day  and  if  very  hot 
should  be  shaded  from  the  sun  and  currents  of  air. 
After  8  or  10  days  the  wall  is  seasoned  and  need 
not  be  bothered  with  longer.  For  the  mixing  and 
handling  of  the  concrete  used  for  this  wall  see 
"Concrete,  etc."  A  proper  composition  for  such  a 
wall  would  be,  cement,  1;  sand,  3,  and  aggregate,  5; 
the  sand  must  be  coarse. 

We  will  present  another  method  of  form  used 
frequently,  having  some  advantages  and  some  dis- 
advantages over  the  box  form  method  described. 
This  is  called  the  frame  form  method,  in  which  2x4 
uprights  are  slightly  set  or  driven  into  the  ground 
along  each  side  of  the  wall  and  four  feet  apart. 
These  must  be  as  true  as  a  line,  plumb  or  battered 
to  suit  for  the  desired  wall.  The  uprights  are  di- 
rectly across  the  wall  from  each  other  with  a  strip 
nailed  across  the  form  at  the  top  and  sufficiently 
high  to  clear  the  top  of  the  wall  when  completed. 
It  will  be  best  to  nail  strips  near  the  top  of  these 
uprights  on  the  one  side  only,  and  let  them  pro- 
ject away  from  the  wall  to  a  stake  firmly  driven 
into  the  ground,  to  which  nail  as  near  the  ground 
as  possible.  This  will  stiffen  the  frame  and  hold 
each  pair  of  uprights  exactly  to  the  place;  when 
these  stand  true  as  the  wall  desired,  place  against 
the  inside  of  these,  2"  x  4"  stiff  boards  of  even  thick- 
ness and  width  if  convenient,  one  board  high  on 
each  side  at  a  time;  when  this  is  filled  as  in  the 
other  case,  another  height  of  boards  are  placed; 
this  is  continued  to  the  height  of  wall,  which  must 
be  level  and  true  to  receive  the  sill  or  joist.  This 
plan  takes  more  lumber,  but  since  it  is  not  nailed 
it  can  again  be  used  for  a  like  purpose,  or  for 
sheathing  if  desired.  The  corners  of  the  wall  must 
be  housed  up  in  like  manner;  windows  and  doors 
may  be  set  as  in  other  method,  also  perpendicular 
joints  carried  through  the  stretches  of  long  walls. 


4  to  24  gauge  steel  and  from  %  to  6-inch  mesh, 
suited  for  all  kinds  of  work.  These  sheets  are  en- 
tirely ^incorporated  in  the  wall  and  reinforce  in 
every  way.  * 

In  wrought  iron  bonding  many  light  rods  at 
closer  intervals  are  much  better  than  fewer  heavy 
ones.  Where  walls  are  reinforced  it  is  not  neces- 
sary to  carry  perpendicular  setting  joints,  very 
The  frame  form  is  removed  after  24  or  36  hours 
and  well  seasoned  as  in  other. 

At  this  point  I  wish  to  say  that  to  make  an  even 
well  filled  face  to  these  concrete  walls  considerable 
attention  should  be  given  to  the  placing  and  tamp- 
ing of  the  concrete.  When  the  aggregate  is  fine 
there  is  little  or  no  trouble,  but  when  coarse,  the 
finer  particles  can  be  kept  near  the  surface  and 
the  coarse  near  the  middle;  take  trowel  and  while 
one  man  is  filling  into  the  form  with  shovel  rake 
the  coarse  particles  back,  and  with  blade  cut  down 
sides,  making  face  more  compact,  when  proper 
tamping  will  do  the  rest. 

In  walls  requiring  great  strength  with  light  body 
of  concrete,  the  work  can  be  armored  or  reinforced 
at  little  additional  cost,  frequently  cheaper,  since  it 
saves  extra  thickness  of  wall.  In  the  more  ordi- 
nary work,  such  as  farm  buildings,  basements,  etc., 
the  reinforcing  is  simple.  Walls  of  no  greater 
height  than  8  or  10  feet  need  only  horizontal  bond- 
ing. Take  rod  iron  bars  1A  x  %  inch;  these  rods 
should  be  twisted  several  rounds  especially  near  the 
ends;  when  one  stretch  of  wall  is  about  two  feet 
high,  lay  upon  this  Vs  way  in  from  one  side  the 
entire  length  of  wall  but  not  protruding  from  the 
corner  or  end,  a  continuous  stretch  of  rods,  lapping 
ends  6  inches  but  not  touching  each  other,  so  that 
concrete  can  encase  each  rod  independently  of  the 
other;  on  the  next  course,  say  a  foot  higher,  lay 
another  stretch,  but  this  time  on  the  opposite  side  % 
way  in  from  surface.  This  can  be  continued  to  the  top 
of  wall.  Where  a  wall  turns  a  corner  the  bonding  of 
metal  should  extend  into  the  corner  from  each  way. 

Where  perpendicular  reinforcement  is  required, 
the  bonding  may  be  done  similar,  by  placing  twisted 
39 


bars  of  suitable  lengths  perpendicular  into  the  con- 
crete at  suitable  distances,  say  every  two  feetA  This 
now  would  make  a  reasonably  good  job  of  horizon- 
tal and  perpendicular  armoring.  Where  still  more 
importance  is  attached  to  the  reinforcing,  expanded 
metal  designed  for  this  use  should  be  used;  this  can 
be  obtained  in  sheets  of  various  sizes,  and  from  Nos. 
necessary  in  ordinary  concrete.  In  retaining  walls 
it  is  sometimes  advisable  to  carry  blind  or  even  ex- 
posed pilaster  at  ends  and  at  regular  intervals  in  the 
wall  and  between  these  and  bound  into  the  pilaster, 
build  up  sheet  walls  from  6  to  12  inches  thick,  rein- 
forced. This  reinforcing  should  be  placed  in  such 
a  way  as  to  truss  the  sheet  wall,  and  hang  the 
sheering  or  crowding  weight  on  the  pilasters,  which 
may  be  done  in  the  following  way:  Place  the  rods 
at  or  near  the  bank  side  of  the  pilasters,  then  ex- 
tend them  forward  so  that  at  the  middle  of  the 
sheet  wall  they  are  within  \Vz  inches  of  the  front 
face.  The  distance  between  these  pilasters,  their 
size,  and  thickness  of  sheet  walls,  also  the  method 
of  reinforcing,  must  depend  on  the  height  of  wall, 
the  nature  of  the  soil  to  be  held  in  place,  etc.,  and 
can  only  be  determined  by  the  engineer. 

Metal  reinforcing  must  never  extend  to  the  sur- 
face so  as  to  be  exposed,  in  which  case  corrosion 
would  follow. 

We  wish  still  to  refer  to  another  kind  of  wall; 
this  is  a  basement  or  cellar  wall.  Where  care  has 
been  exercised  in  the  excavation  for  basement  walls, 
it  is  sometimes  only  necessary  to  carry  the  outside 
face  with  a  form,  the  back  side  can  be  built  against 
the  bank.  In  such  a  case  use  frame  form,  2x4  up- 
right, secured  in  ground  at  bottom,  and  on  top,  held 
in  place  by  strip  of  board  nailed  to  stake  on  bank; 
against  this  place  suitable  boards  as  the  wall  is 
carried  up  to  the  grade  line.  From  this  point  the 
wall  can  be  carried  to  the  sill  line,  but  will  require 
an  additional  form  for  the  face  of  the  ashler  work. 
But  if  the  excavation  is  too  irregular,  or  wide,  caus- 
ing waste  of  concrete,  then  it  would  be  best  to  use 
the  double  frame  form,  or  the  box  form,  already  de- 
scribod. 

40 


Cellar  walls  for  frame  buildings  should  be  from 
10  to  12  inches  thick,  ordinary  concrete.  For  brick 
14  to  24,  according  to  the  thickness  of  the  brick  wall; 
for  these  two  only  ordinary  concrete  is  required 
Barn  walls  should  be  as  wide  on  top  as  sill  and  may 
have  wider  footings  at  bottom  or  battered  as  the 
weight  and  the  height  of  the  wall  would  most  re- 
quire. Where  a  barn  has  a  bank  wall,  such  as  used 
in  some  of  the  states,  for  a  drive  above  basement, 
this  bank  wall  should  be  from  18  to  30  inches  at 
bottom  and  from  14  to  20  inches  on  top;  this  will 
allow  room  for  joists  to  rest  on  the  wall,  say  6  to  10 
inches,  and  still  leave  room  for  concrete  door  sill 
coming  up  even  with  top  of  floor  and  against  the 
top  of  which  the  door  can  close;  this  sill  is  built  in 
the  following  way:  When  the  joists  are  laid  anc" 
barn  up,  place  board  along  the  end  of  joists  extend- 
ing across  floor  to  posts,  and  high  enough  to  come 
to  top  of  floor  line;  place  another  board  along  the 
outside  to  conform  to  door  line  and  two  inches  lower 
than  inside  one,  secure  this  so  it  cannot  shove  out 
of  place  when  concrete  is  tamped  into  it.  Place  the 
concrete,  tamp  and  stroke  even;  any  time  after  24 
hours  the  outside  form  board  can  be  removed;  the 
inside  one  is  left. 

The  various  walls  needed  about  the  house  or 
farm  can  be  constructed  in  a  similar  way  to  the 
methods  herein  given,  and  we  will  not  dwell  on  fur- 
ther explanations. 

A  few  fundamental  requirements  for  all  walls, 
either  stone,  brick  or  concrete,  we  think  will  not  be 
amiss.  A  foundation  must  extend  through  the  frost 
line.  A  foundation  must  extend  through  soft  or 
yielding  soil. 

Cobble  stone  and  other  porous  foundations  must 
have  drains  from  the  lowest  point  of  the  trench, 
otherwise  they  are  worse  than  no  foundation,  be- 
cause the  water  settling  in  softens  the  bed  and  in 
freezing  weather  causing  heavings,  followed  by  ex- 
cessive settlings.  If  the  three  cautions  referred  to 
are  strictly  observed  walls  will  remain  intact  and 
stand  as  when  built  for  time,  otherwise  the  best  and 
most  carefully  finished  walls  will  be  broken,  yield- 
41 


ing  and  unsightly  after  a  few  years.  In  localities 
where  field  stone  are  abundant,  especially  for  farm 
work,  where  the  farmer  must  pick  them  from  his 
meadows  each  year  and  have  many  loads  hauled  on 
piles,  which  can  be  had  in  many  cases  for  the  haul- 
ing, these  can  be  used  for  such  wall  purposes,  and 
for  method  of  using  see  "Mortar  Concretes."  Pillars 
for  sheds,  grain  houses,  etc.,  can  easily  be  built  in 
this  way  by  first  making  suitable  form.  It  should, 
however,  be  remembered  that  in  the  construction 
of  all  forms,  that  they  must  be  so  made  as  to  be 
removed  when  desired,  without  pounding  or  in  any 
way  crowding,  straining  or  breaking  the  cast.  Dur- 
ing warm  or  drying  weather  walls  6  or  8  days  old 
are  ready  for  the  buildings. 

Floors — Cellar  or   Basement,, 

Where  there  is  no  frost  to  penetrate  beneath  the 
bed,  walks  are  at  once  laid  on  the  hard  ground,  first 
evened  off  to  bring  the  top  of  the  concrete  to  the 
desired  height  and  grade.  These  floors  will  range 
in  thickness  from  2*/2  to  4  inches,  according  to  use. 
For  floor  3  inches  thick,  first  place  over  the  bottom 
concrete  2l/2  inches  thick  well  tamped  down;  for 
ordinary  purpose  this  concrete  can  have  the  follow- 
ing proportions:  Cement,  1;  sand,  3;  aggregate,  5 
parts.  Over  this  concrete  spread  with  float  or 
trowel  evenly,  ^-inch  plastic  mortar,  made  from 
sand  and  cement  in  the  following  proportions:  Ce- 
ment, 1  part;  sand,  2  or  3  parts  (2  parts  if  fine,  3 
if  coarse.  This  can  be  laid  in  one  continuous  block 
and  as  soon  as  one  can  walk  on  it  without  leaving 
marks,  it  should  be  sprinkled  each  day  for  6  days. 
Stable,  Shed  and  Barn  Floors. 

Under  this  we  have  reference  only  to  floors  sup- 
ported by  the  ground  and  do  not  include  suspended 
floors  of  which  we  shall  speak  later.  For  these 
floors  excavate  all  loose  or  yielding  soil  and  suffi- 
ciently deep  enough  that  from  9  to  12  inches  of 
porous  foundation  can  be  placed  below  the  floor; 
this  may  consist  of  cobble  stone,  gravel,  cinders, 
etc.,  and  must  be  evenly  placed  and  tamped,  so  that 
no  uneven  settling  may  occur,  which  would  check 
the  blocks.  This  porous  foundation  must  have  an 
42 


outlet  at  the  lowest  point  so  that  no  water  will  sec 
in  the  foundation  causing  heaving  in  freezing 
weather.  The  foundation  done  we  are  now  ready 
for  the  floor.  This  may  vary  in  thickness  from  3  to 
6  inches,  and  should  not  be  laid  in  one  continuous 
floor,  but  blocked  into  nearly  square  blocks,  which 
should  measure  on  their  sides  in  feet  most  nearly 
twice  their  thickness  measured  in  inches,  thus  a  floor 
4  inches  thick  should  lay  in  blocks  8  x  8  or  64  square 
feet.  A  floor  for  foot  use  need  be  only  3  inches 
thick;  for  horses  and  wagons,  4  to  5  inches;  stalls 
for  cattle,  3V2  to  4  inches.  In  some  cases  these 
blocks  can  conform  in  size  to  the  stalls,  thus  over- 
coming the  need  of  remnant  or  smallish-sized  blocks. 
The  composition  of  the  concrete  for  these  floors 
would  be  amply  safe  at,  cement,  1  part;  sand,  3 
parts;  aggregate,  5  parts.  On  the  top  of  concrete 
spread  mortar  nicely  even,  made  of  cement,  1  part; 
sand,  2  or  3  parts.  The  thickness  of  this  mortar 
can  vary  from  ^  inch  on  foot  floors  to  1  and  11A 
on  stable  floors,  thus  the  3-inch  floor  would  consist 
of  concrete,  2^  inches,  and  plastic  mortar,  %  inch; 
the  4-inch  floor,  concrete,  3  inches;  mortar,  1  inch; 
the  5-inch  floor,  concrete,  3%  inches;  mortar,  l1^ 
inches,  and  the  blocks  would  be  6  feet  square,  8  feet 
square  and  10  feet  square.  In  stables  for  cattle 
and  horses,  etc.,  there  should  be  dr«in  cups  at  the 
proper  location  in  the  stalls  with  the  surface  of  the 
stall  inclined  to  them  so  that  liquid  matter  will  at 
once  be  carried  away  from  the  stall.  These  drain 
cups  consist  of  perforated  cast  iron  drain  lids  or 
tops  about  6  or  8  inches  in  diameter;  the  holes 
should  be  ^  inch  at  top  and  Vz  inch  at  bottom; 
these  will  not  clog.  For  a  6-inch  drain  cup  the  hole 
through  the  floor  should  be  4  inches  so  that  the  lid 
may  have  a  bearing  of  1  inch  around  the  circle  or 
outer  edge.  This  flange  or  collar  which  holds  the 
drain  lid  and  into  which  it  lays  with  the  top  %  inch 
lower  than  the  surface  of  the  floor  next  to  it,  should 
be  3/16  of  an  inch  larger  in  diameter  than  the  drain 
lid  so  that  it  can  easily  be  removed  and  the  tile  or 
sewer  beneath  it,  and  into  which  it  drains,  can, 
when  necessary,  be  flushed  or  cleaned. 
43 


In  the  city  the  tiles  from  these  cups  should  be 
carried  into  the  sewer;  in  the  country  they  should 
lead  into  the  compost  (manure)  yard  or  liquid  tank. 

How  to  place  the  sewer  pipe  connecting  these 
cups,  etc.:  First,  put  in  the  porous  foundation  for 
the  floor  with  exact  grade  on  top  to  receive  the 
floor.  'Ascertain  the  exact  location  of  the  line  sew- 
ers in  back  end  of  stalls,  now  along  this  line  with 
true  and  equal  fall  lay  4-inch  collar  sewer  pipe,  con- 
necting all  the  stalls  in  this  stable  and  extending 
with  sufficient  fall  into  the  barnyard  or  where 
wanted.  These  tile  may  extend  above  this  porous 
foundation  1  inch  and  in  laying  the  joints  must  all 
be  made  water  tight  by  using  mortar  jointing,  and 
should  also  be  laid  in  mortar  so  that  they  will  not 
move  when  placing  concrete.  At  each  stall  where 
open  cup  is  wanted,  place  sewer  with  collar  open- 
ing made  for  this  and  similar  uses.  Upon  this  hole 
build  the  drain  cup  and  with  sufficient  care  that  it 
may  not  leak.  Some  connections  between  drain  cup 
and  sewer  may  be  longer  than  others,  but  these  can 
be  built  up  any  lengths  by  placing  a  4-inch  turned 
stick  or  plug  into  the  hole  of  the  tile  and  letting  it 
extend  up  above  the  floor  line.  When  laying  the 
concrete  tamp  around  this,  or  better,  place  around 
it.  When  ready  for  the  top  mortar  gently  remove 
these  plugs,  which  would  be  slightly  tapered  at  bot- 
tom, to  allow  their  easy  removal.  On  the  top  of 
this  concrete  lay  the  perforated  lids  and  when  build- 
ing mortar  around  them,  when  partly  set,  take 
spike,  insert  into  one  of  the  holes,  and  slightly 
move  the  lid  sidewise  until  the  collar  is  sufficiently 
large  to  admit  their  removal. 

How  to  divide  the  floor  into  blocks.  For  illustra- 
tion we  will  take  a  wagon  shed  floor;  the  shed  is 
16  x  30  feet,  the  floor  is  4  inches  thick.  Procure 
scantling  2x4  inches  and  straight;  set  this  cross- 
wise 8  feet  from  the  furtherest  end  of  the  wall  of 
the  shed.  (In  this  we  have  supposed  the  foundation 
already  down.)  Across  this  section  16x8  feet  in 
the  middle  place  another  2  x  4  on  edge  8  feet  long, 
these  must  not  be  nailed,  but  secured  in  place  by 
proppings  or  stakes,  or  could  be  secured  by  laying 
44 


a  few  sacks  of  cement  against  the  outer  edge.  Mix 
the  concrete  and  place  one  section  even  full,  tamp 
well,  when  within  1  inch  of  the  top  of  the  form, 
which  can  be  ascertained  with  straight  edge,  remove 
cross  form  (2x4)  and  mark  with  pencil  on  form, 
and  on  opposite  wall  the  exact  edge  of  this  block, 
so  that  when  the  mortar  is  placed  and  spread  over 
this  that  in  cutting  this  top  you  can  strike  the  exact 
joint  in  the  concrete  below.  Against  this  joint  now  . 
made  bare  by  the  removal  of  the  form,  place  several 
thicknesses  of  paper,  3/16  inch  (cement  sack  paper 
would  do),  place  concrete  for  the  next  block  in  the 
same  way  as  the  first;  when  this  is  done,  with  shears 
cut  the  paper  off  that  extends  above  the  concrete. 
Now  over  this  place  mortar  and  with  straight  edge 
resting  on  the  form  stroke  off  even  with  form,  even 
nicely  with  wooden  float.  If  desired  mark  edges 
with  cement  edger,  and  at  the  joint  of  the  two  blocks 
lay  straight  edge  and  with  trowel  cut  top  through 
along  the  joint;  with  double  jointer  follow  through 
this  cut,  and  the  two  blocks  are  done.  Now  set  the 
16-foot  2x48  feet  further  away,  secure  again  and 
continue  as  before,  only  this  time  make  two  half 
blocks  at  each  side  with  whole  one  in  middle,  etc. 

If  it  is  desired  to  place  a  drain  cup,  used  in  wash- 
ing buggies,  this  can  easily  be  done  same  as  in 
sewer  cups  in  stables;  however,  the  surface  grade 
must  conform  to  cup  for  this  purpose. 

As  soon  as  this  surface  bears  one  up  without 
marks  (perhaps  from  24  to  36  hours)  sprinkle  thor- 
oughly twice  each  day  for  6  or  8  days.  Horses 
sharply  shod  should  not  be  taken  on  this  for  28  days. 

For  methods  of  mixing  and  using  mortar  and 
concrete,  see  under  Mortar  and  Concrete. 

In  seasoning  floors  it  will  not  be  necessary  to 
cover,  but  in  warm  and  windy  weather  close  win- 
dows and  doors  to  prevent  currents  of  air  which 
would  evaporate  the  moisture  from  the  surface.  In 
some  cases  a  door  sill  will  be  required,  against  which 
the  door  will  close.  This  can  be  put  in  with  the 
floor  by  first  excavating  deep  enough  so  that  the 
frost  will  not  heave;  place  board  or  plank  along  out- 
side or  door  line,in  height  2  inches  lower  than  floor, 
45 


meet  the  floor  line  8  inches  in  from  face  of  sill, 
this  makes  an  easy  wheel  riser,  and  is  most  suit- 
able in  implement  and  wagon  shed.  Just  before  the 
top  coat  is  set  take  wall  edger  or  trowel  and  dub 
off  sharp  corner  on  outer  edge  of  sill,  so  that  it  will 
not  chip  off  with  use.  In  laying  floors  with  con- 
crete and  mortar  top  as  described,  it  should  be  re- 
membered that  when  the  concrete  is  once  laid  the 
mortar  top  must  be  placed  before  the  concrete  has 
set,  which  in  drying  weather  would  be  about  2  hours. 
When  this  occurs  with  work  left  unfinished  during 
night,  the  matrix  may  be  renewed  by  sprinkling 
water  over  the  surface  and  with  a  fine  sieve  sprin- 
kling cement  lightly  over  same. 

Floors   Supported  on  Joist. 

Floors  of  concrete  reinforced  are  now  almost 
everywhere  used  in  all  extensive  buildings.  Germany 
and  France,  it  may  be  said,  were  the  pioneers  in  this 
method  of  fire-proofing.  It  is  not  so  new  as  many  in 
this  country  seem  to  think.  Our  engineers  were 
slow  to  endorse  its  use  at  first,  but  today  there  is  not 
a  Building  of  any  note  being  built  that  does  not  con- 
tain some  form  or  other  of  this  fire-proofing. 

The  large  fires  in  the  cities  continually  justify 
the  wisdom  of  their  use,  and  without  them  the  tall 
office  building,  the  large  tenement  house  and  fac- 
tory would  be  an  impossibility.  A  suite  of  rooms 
with  their  contents  are  frequently  rid  by  fire  of 
every  combustible  article,  without  any  dismay  to 
the  tenant  on  the  opposite  side  of  the  wall  or  floor. 
In  factories  and  large  shops  where  heavy  machinery 
is  placed  these  floors  are  frequently  solid,  the  bot- 
tom of  the  floor  forming  the  ceiling  beneath,  and 
entirely  encasing  the  heavy  steel  or  reinforced  con- 
crete beams,  which  supports  the  expanded  metal  or 
corrugated  wrought  iron  netting  which  is  incased 
in  the  concrete,  and  forms  one  solid  mass.  In  office, 
tenement  and  dwelling  house,  the  floors  and  ceiling 
are  independent  of  each  other,  the  beams  or  joists 
are  usually  of  steel,  the  floor  takes  its  bearing  over 
the  top  and  on  the  lower  flanges,  differing  with  the 
many  methods  in  use.  The  concrete  is  laid  on  false, 
removable  bottoms;  when  about  %  of  the  concrete 

46 


is  tamped  into  place  the  metal  reinforcing  is  placed 
on  this,  usually  expanded  sheet  steel;  over  this  and 
into  its  meshes  connecting  the  whole  into  one  mass, 
the  balance  of  the  concrete  is  placed;  the  floor  is 
finished  on  top  in  different  ways,  in  shops  mostly 
with  mortar  top  as  already  described,  in  other  build- 
ings tiles  are  frequently  used  and  in  many  screeds 
or  nail  strips  are  placed  on  top  with  concrete  be- 
tween and  on  this  a  wooden  floor  is  laid.  In  cinder 
concrete  the  floors  are  frequently  nailed  directly 
into  this  concrete.  In  dwellings  and  other  build- 
ings in  some  cases,  strips  are  spiked  on  the  sides 
of  wooden  joists,  boards  are  sawed  in  lengths  to  fit 
into  this,  the  concrete  is  placed  on  this  and  extended 
a  few  inches  above  the  joists,  when  screeds  are 
placed  and  the  floor  nailed  to  the  top  of  these,  with 
a  suspended  ceiling.  This  has  proven  fire-proof. 
Highway  bridge  floors  are  now  in  most  cases  con- 
structed in  a  similar  way  as  already  described,  while 
the  fire-proofing  in  this  is  not  required,  yet  in  tip 
best  work  the  steel  must  be  entirely  covered  to  avoid 
corrosion.  The  thickness  of  floors  will  differ  with 
use  to  which  they  are  put;  the  distance  between 
joists,  and  also  to  the  method  of  reinforcing.  Since 
this  will  be  a  work  specially  in  the  hands  of  the 
engineer,  we  shall  make  no  further  effort. 

Ceilings 

for  fire-proofing  are  usually  suspended  from  the 
joists  by  hangers  made  for  this  purpose.  These  sup- 
port the  metal  lathing  against  which  the  plastering 
is  placed;  the  space  between  this  and  the  floor  con- 
taining the  piping  and  wiring.  This  same  fire- 
proofing  is  also  applied  to  the  rafters. 

Partitions. 

These  are  used  in  fire-proof  buildings  and  consist 
of  solid  or  hollow  wall.  The  solid  partition  is  built 
up  same  as  wall  with  two  face  forms  supported 
against  frame  or  uprights.  In  the  middle  of  this 
concrete  wall  is  incorporated  continuous  sheets  of 
expanded  metal.  This  wall  is  continued  firmly 
against  the  floor  above;  the  metal  gives  it  support 
fundamental  methods;  these  must  be  varied  to  each 
and  adds  elasticity.  In  thickness  this  can  be  car- 
47 


ried  to  suit  the  work,  usually  from  3  to  •  inches. 
The  hollow  partition  is  studded  and  with  metal  fas- 
tenings the  metal  lathing  is  held  from  the  studding 
on  either  side,  this  is  plastered  with  heavy  coat  cf 
mortar  on  each  side.  The  side  walls,  wooden  beams, 
etc.,  are  fire-proofed  in  this  same  way  by  metal  lath- 
ing supported  from  the  studding,  etc.  In  this  build- 
ing the  mop  boards,  some  casings  and  molding  are 
also  made  from  cement  with  suitable  molds.  In 
light  work  only  fine  aggregates  can  be  used. 

Walks. 

This  embraces  a  very  important  and  extensive 
line  of  cement  work,  and  requires  the  most  exacting 
care  in  the  labor  and  the  selection  of  materials. 
First  in  order,  and  as  well  first  in  poir4-.  of  impor- 
tance, is  the  excavation  for  the  foundation  of  the 
walk.  This  must  be  dug  3  inches  wider  on  each  side 
than  the  width  of  walk  so  as  to  have  room  for  the 
form,  and  must  not  be  sloped  in,  but  be  excavated 
perpendicular  at  sides,  so  that  no  lifting  will  occur 
in  freezing.  In  clay  land  this  excavation  must  be 
deep  enough  to  admit  of  porous  foundation  12  or  15 
inches  thick  on  which  the  walk  is  built.  In  sandy 
soil  6  to  8  inches  would  be  equally  good.  To  secure 
a  well  dug  excavation  stretch  line  on  each  side — 
these  lines  must  conform  to  walk  and  grade  line. 
From  these  a  uniform  depth  can  be  gauged.  When 
excavation  is  completed,  if  in  clay,  it  is  imperative 
that  a  tiled  drain  be  placed  from  the  lowest  point 
of  the  excavation  to  a  lower  outlet,  so  that  the  water 
will  not  stand  in  this  porous  foundation,  and  in  cold 
weather  freeze,  causing  expansion  and  the  breaking 
of  the  walk.  When  this  is  completed,  place  the  ma- 
terials for  the  foundation;  this  may  consist  of  cobble 
stone,  coarse  gravel,  cinders,  slag  or  shells;  these 
should  be  evened  and  rammed  solid  as  they  are 
placed  into  the  trench.  Stone  should  be  sledged  and 
lighter  materials  tamped  with  iron  tamper.  The 
common  practice  of  filling  these  trenches  by  shovel- 
ing cinders,  etc.,  from  wagon  without  evening,  etc., 
and  often  allowing  it  to  be  used  for^  walk  (path 
through  middle)  for  some  time  before  it  is  used,  is 
very  objectionable,  and  has  proven  ruinous  to  many 
48 


walks  otherwise  well  made.  The  regular  walk 
builder  will  have  heavy  iron  roller  with  which  the 
cinders  or  gravel  are  kept  evenly  packed  when  put 
in.  It  is  not  so  much  that  they  are  tamped  hard  as 
that  they  are  even  (edges  and  middle  alike).  When 
the  foundation  is  brought  up  to  the  bed  of  the  walk 
the  forms  are  placed  for  the  walk.  The  forms  con- 
sist of  2-inch  scantling  set  on  edge,  and  in  widtv 
being  the  height  of  the  thickness  of  the  walk  (coi^ 
crete  and  mortar  top);  these  scantling  side  forms 
are  laid  with  line,  so  that  the  walk  will  be  true  to 
grade  and  lot  line  when  completed.  The  forms  are 
held  from  crowding  out  by  stakes,  etc.,  sufficiently 
close  that  no  bulging  can  occur  when  the  concrete 
is  tamped  into  place* 

The  scantlings  are  held  in  place  from  the  inside 
by  the  cross  scantlings  put  in  at  regular  distances 
and  at  right  angles  with  the  side  forms.  These  are 
used  in  dividing  the  walk  into  equal  sized  blocks,  as 
the  concrete  is  placed  into  each  space  they  are  re- 
moved and  placed  forward  «for  new  blocks.  Where 
curves  are  desired  in  the  walk,  narrow  boards  are 
used  instead  of  the  scantlings.  These  can  be  sprung 
to  suit  the  curve,  but  greater  care  must  be  taken  to 
hold  them  in  place,  so  they  will  not  crowd  between 
stakes  in  tamping.  Walks  are  usually  laid  with  1A 
inch  inclination  per  foot  towards  the  road  side  of  the 
walk,  shedding  the  water  into  the  gutter. 

The  form  placed  we  are  ready  for  the  concrete, 
but  before  placing  this  we  should  understand  some 
of  the  preliminaries  of  walk  construction. 

Walks  are  constructed  of  a  layer  of  concrete,  and 
upon  this  a  mortar  top  is  spread;  also  walks  are  not 
built  in  one  continuous  stone,  but  in  blocks  of  unit 
form  size,  and  most  nearly  square.  This  must  be  de- 
termined by  the  width  of  v/alk,  thickness  of  blocks,  etc. 

We  herewith  give  table  for  relative  size  and 
thickness : 

Walk  2  ft.  wide  should  be  3  1-2  in.  thick  and  2x4  ft.  block 
Walk  3  ft.  wide  should  be  4  in  thick  and  3  x  4  ft.  block 
Walk  4  ft.  wide  should  be  4  in.  thick  and  4  x  5  ft.  block 
Walk  5  ft.  wide  should  be  4  1-2  in.  thick  and  5  x  5  ft.  block 
Walk  6  ft.  wide  should  be  5  in.  thick  and  6  x  6  f t.  block 
Walk  8  ft.  wide  should  be  6  in.  thick  and  8  x  8  f  t.  blocl* 
49 


^  thicknesses  given  include  concrete  and  mor- 
tar top,  and  is  designed  for  the  most  exacting  use. 

In  dividing  walks  into  blocks  there  are  several 
methods  employed.  One  is  to  place  the  cross  form 
along  the  walk  to  correspond  to  the  size  here  given, 
fill  this  section,  tamp,  and  then  remove  cross  form. 
Against  this  joint  thus  made  bare,  plaster  clay  or 
loam  mortar  &  inch  thick,  or  place  paper,  or  felt  % 
inch,  or  against  it  set  a  steel  divider  6  inches  high 
and  ^4  inch  thick.  The  steel  divider  is  perhaps  the 
most  convenient  for  the  regular  workman.  If  three 
men  are  at  work  from  6  to  10  of  these  blocks  can 
be  made  in  this  way  with  concrete  before  the  top 
mortar  is  placed.  Now,  by  slightly  tapping,  remove 
the  steel  divider  leaving  the  joint  dividing  the  stone 
open;  if  paper  was  used,  with  shears  trim  off  the 
paper  projecting  above  the  concrete;  if  clay  was 
used  this  is  ready.  Now  with  knife  or  pencil  mark 
on  top  of  each  side  form,  exactly  over  the  division 
of  concrete  block  so  that  when  the  mortar  is  placed 
and  ready  to  cut  into  blocks,  by  laying  straight  edge 
to  these  marks  we  can  cut  with  trowel  through  the 
top  mortar  exactly  into  this  division  space  below. 
If  these  are  not  exactly  met  the  mortar  or  top  sur- 
face will  check  across  even  with  the  lower  joint,  thus 
impairing  the  work. 

Two  formulas  for  concrete  for  walks: 

No.  1 — Cement  1,  sand  2,  aggregate  4  to  5  parts. 

No.  2 — Cement  1,  sand  3,  aggregate  6  to  8  parts. 

No.  1  would  answer  for  the  best  class  of  work 
(city  wear),  No.  2  would  be  suitable  for  ordinary 
work,  but  in  this  the  sand  and  aggregate  should  be 
well  graded.  For  the  best  methods  of  mixing  and 
handling,  also  as  to  the  selection  of  sand  and  aggre- 
gate, see  Part  III,  on  Concretes. 

Two  formulas  for  mortar  for  walks: 

No.  1 — Cement  1,  sand  1  to  2  parts. 

No.  2 — Cement  1,  sand  2  to  3  parts. 

Formula  No.  1  would  represent  mortar  equal  to 
the  most  exacting  use.  No.  2  ordinary. 

For  best  methods  of  mixing  and  handling  mortar, 
see  Part  II. 

Where  extraordinary  resistance  to  wear  must  be 
50 


secured  crushed  granite  chips,  or  flinty  pebbles  are 
incorporated  in  the  top  mortar;  this,  however,  is  sel- 
dom necessary  if  the  best  hard  and  clean  sand  is 
used.  For  sake  of  more  minute  illustration  we  will 
build  walk  6  feet  wide  and  5  inches  thick;  concrete  4 
inches  and  mortar  top  1  inch.  Measure  carefully 
and  mix  according  to  directions  under  "Concrete." 
When  mixed  and  before  placed  take  sprinkling  can 
and  sprinkle  foundation  and  side  forms  so  the  dry 
surfaces  will  not  evaporate  the  water  from  the  con- 
crete. When  this  is  done  place  concrete  and  with 
concrete  tamper  tamp  dense  and  evenly,  when  water 
will  slightly  appear  on  surface.  If  the  concrete 
quakes  it  is  an  indication  that  too  much  water  was 
used  in  mixing.  The  placing  of  the  forms  has  been 
described,  and  in  this  case  will  be  5  inches  high  and 
the  blocks  6x6  feet.  In  order  to  gauge  off  the  con- 
crete for  this  walk  use  straight  edge  6^  feet  long; 
this  will  leave  3  inches  at  each  end  to  slide  on  the 
side  forms;  notch  the  straight  edge  1  inch  deep  and 
4  inches  long  in  from  each  end;  now  by  placing  these 
notched  ends  on  the  form  at  the  sides  and  stroking 
along,  this  will  leave  the  concrete  1  inch  below  the 
top  edge  of  the  forms,  this  space  to  be  occupied  by 
the  mortar  top.  When  this  block  is  finished  in  this 
way,  even  and  well  tamped,  remove  the  joint  or  cross 
form,  and  place  forward.  Space  another  block  6 
feet  with  run  of  the  walk;  after  treating  joint  ex- 
posed as  directed  in  "The  Division  into  Blocks;"  fill 
this  section  the  same  way.  This  can  now  be  con- 
tinued the  whole  length  of  the  walk,  if  the  force  is 
so  divided  that  some  follow  placing  the  top  mortar 
before  the  top  dries,  or  within  2  hours  after  con- 
crete is  laid.  Otherwise  the  concrete  men,  after 
placing  several  blocks,  must  return  and  place  the 
top  mortar.  Some  care  is  required  to  keep  the  faces 
or  edges  of  the  sides  full  and  dense;  this  can  be  done 
by  keeping  finer  concrete  near  the  side  surface,  and 
close  tamping.  The  cross  forms,  called  joint  forms, 
must  not  be  nailed,  but  held  in  position  some  other 
way  so  that  no  pounding  will  be  required  to  remove 
them. 

We  will  now  place  the  mortar  top.     Notch  or 


mark  all  the  cross  joints  as  directed,  with  trowel  re- 
move all  dry  and  loose  concrete,  etc.,  near  side  edges 
and  from  form.  Slightly  sprinkle  side  forms  again, 
also  surface  of  concrete  if  dry.  Place  mortar  and 
with  trowel  spread  heavily  on  the  surface  of  the 
concrete;  watch  that  in  using  the  trowel  in  the 
mortar  no  air  spaces  are  covered;  also  use  trowel 
along  sides  so  that  the  edges  will  become  dense. 
Do  not  try  to  smooth  surface  with  trowel,  but  when 
spread  over  the  surface  so  that  it  will  stroke  safely 
full,  take  a  straight  edge,  the  back  of  the  concrete 
straight  edge  will  do,  if  straight;  with  this  resting 
on  the  side  forms  stroke  the  mortar  off  even.  In 
holding  straight  edge  slightly  slanting  it  will  pack 
the  mortar  some.  When  the  space  for  several  blocks 
is  thus  spread  leave  it  for  about  20  minutes,  or  until 
the  water  on  the  surface  is  about  evaporated,  when 
with  wooden  or  cork  float,  dipped  into  the  water, 
float  the  top  surface.  Do  not  float  heavily  so  as  to 
shove  the  mortar,  but  slightly,  so  as  to  compact  the 
surface,  and  at  the  same  time  give  it  an  even,  un- 
marked appearance.  Do  not  use  steel  trowel  for 
this  purpose,  it  gives  it  a  glossy,  streaked  and  cheap 
appearance,  and  in  which  hair  checks  may  follow. 
With  a  trowel  run  along  side  forms  as  far  as  fin- 
ished, cutting  about  1  inch  deep,  and  holding  it  in 
such  a  way  as  to  crowd  the  mortar  back  from  the 
form  about  %  inch,  then  lay  the  straight  edge  across 
the  walk  at  the  marked  joint  places  and  with  trowel 
sliding  against  side  cut  the  top  mortar  through  into 
the  space  of  the  concrete  below.  In  cutting  across 
walk,  hold  trowel  to  cut,  and  avoid  dragging  and 
tearing  the  edges. 

Now,  to  finish,  take  suitable  sidewalk  edger, 
place  cutter  into  trowel  cut,  slide  along  side  form  the 
whole  length  finished;  repeat  on  other  side  in  the 
same  way,  pressing  only  hard  enough  to  make  an 
even  and  straight  furrowed  edge  about  1/16  inch 
deep.  With  sidewalk  jointer  pass  through  the  cross 
joint  at  the  place  cut  with  trowel;  this  completes  the 
walk  so  far.  This  is  repeated  until  the  entire  length 
is  laid.  Mortar  for  the  top  of  walk  should  not  be 
too  wet,  only  sufficiently  to  work  slightly  plastic  for 
52 


use.     If  too  wet  suspended  water  In  the  mass 
rise  to  the  surface  causing  pock  marks. 

In  ordinary  drying  weather,  after  24  hours  tnis 
walk  should  be  covered  from  the  sun,  and  currents 
of  air.  This  covering  may  be  whatever  is  most  con- 
venient, either  saw  dust,  shavings,  straw,  grass, 
cloth  or  paper.  Freshly  cut  grass  is  aboui  the  best 
thing  when  it  can  be  had,  though  anything  that  will 
absorb  water  and  that  can  be  sprinkled  without  re- 
moving can  be  used.  When  this  covering  is  placed 
sprinkle  thoroughly,  repeat  twice  each  day  for  6 
days  and  the  walk  is  ready  for  use;  remove  covering 
and  side  forms. 

It  is  a  little  difficult  to  set  forms  for  walks  so 
that  while  they  are  secure  enough  that  at  the  same 
time  they  can  be  so  easily  removed  as  not  to  wrench 
or  jar  the  cast,  but  with  a  little  originality  of  method 
one  can  always  find  some  easy  way  to  secure  these; 
in  some  cases  he  might  fill  against  the  outside  of 
form  ground  slightly  tamped,  or  by  driving  stakes 
away  from  the  form  and  blocking  out.  We  could 
give  no  fast  rules  for  this  work,  since  the  conditions 
for  each  job  may  differ. 

Three  men  who  are  accustomed  to  laying  walks 
will  lay  360  square  feet  of  5-inch  walk  per  day.  The 
amateur  workman,  if  he  possesses  a  25-cent  trowel, 
could  lay  walks  not  inferior  in  quality,  though  per- 
haps inferior  in  looks,  without  any  other  sidewalk 
tools.  The  edger  and  jointer  should  be  dispensed 
with;  the  edges  and  joints  could  be  dubbed  off  with 
trowel,  and  for  want  of  an  iron  concrete  tamper  a 
wooden  tamper  could  easily  be  made  that  would 
serve  one  in  a  small  way  for  his  own  work.  In 
walks  the  mixing  of  concrete  and  mortar  must  be 
thorough,  slighted  work  will  show,  and  be  unre- 
liable; also  excessive  troweling  of  the  top  must  be 
avoided,  especially  if  wet,  as  this  brings  the  finer 
particles  of  cement  out  of  the  sand  and  to  the  top, 
giving  it  what  is  called  a  "skin  cover,"  in  which  hair 
cracks  will  soon  appear,  rupturing  this  glossy  top 
skin,  when  directly  beneath  this  the  surface  is  loose, 
being  mostly  sand,  since  in  the  suction  of  the  trow- 
eling the  cement  floated  with  the  water  to  the  tof 
53 


while  the  coarser  and  heavier  sand  settled  down,  con- 
sequently beneath  thi?  skin  cover  there  is  imperfect 
crystallization. 

Drives. 

This  work  does  not  differ  in  any  way  from  walks, 
only  that  they  must  be  built  to  stand  heavier  and 
rougher  usage.  Drives  should  be  from  6  to  10  inches 
in  thickness,  according  to  use,  and  the  top  mortar  or 
stone  from  V2  to  2  inches  thick. 

Walk  crossings  should  have  wheel  risers  or  ap- 
proaches built  to  them  on  each  side;  these  must  have 
bed  and  thickness  same  as  the  drive.  While  the  top 
of  the  riser  projects  downward  to  meet  the  road  line 
the  bottom  must  incline  in  the  same  way  so  as  to 
maintain  its  strength.  When  the  mortar  top  has 
been  laid  long  enough  after  being  floated  even,  to 
work  heavy,  pass  over  the  surface  with  grooved 
roller,  this  will  give  it  a  ribbed  appearance,  making 
a  safer  footing  for  horses.  A  good  driveway  is 
built  with  slightly  raised  road  bed,  shallow  gutters 
and  curbing. 

Curbing. 

These  are  portable  and  monolithic  in  the  build- 
ing. Most  curbing  are  built  in  the  factory  and  after 
seasoning  are  hauled  to  the  place  where  they  are  set. 
But  under  this  heading  we  shall  endeavor  to  describe 
the  building  or  forming  on  the  spot  where  used. 
Usually  curbing  are  from  6  to  8  inches  thick  and 
from  1  1-2  to  2  1-2  feet  wide.  They  are  built  in  a 
straight  line  between  street  gutter  and  walk,  and 
must  conform  to  street  grade  and  lot  line.  Their  use 
is  to  hold  the  paving  blocks  and  form  the  gutter 
line  on  the  street  side,  and  on  the  walk  side  protect 
the  bank  from  washing.  On  the  gutter  side  they 
project  above  the  paving  from  6  to  10  inches.  On 
the  walk  or  lawn  side  they  are  even,  the  ground 
filled  to  the  top. 

Excavate  trench  for  the  curbing  to  the  depth  de- 
sired; make  form  in  the  following  manner:  take  two 
or  three  planks  for  each  side  to  make  the  height  de- 
sired; strip  these  at  each  end  and  in  the  middle, 
with  the  strips  on  the  outside;  the  sides  should  be 
S1/^  feet  long.  Securely  nail  boards  against  one  end 
54 


of  these  sides  (sawed  square),  giving  the  form  the 
space  inside  desired  for  the  thickness  of  the  curbing, 
with  two  notched  strips  to  slip  over  top  to  hold  in 
place,,  and  the  form  is  ready  for  use.     Set  the  form 
into  the  trench  with  closed  end  in  direction  in  which 
you  desire  to  build.     Set  form  with  a  line  stretched 
true  to  grade  and  street;   this  may  be  secured  by 
shoving  slight  blocks  beneath  the  frame  to  support 
it  in  height  to  line;  blocks  at  the  side  if  needed  be- 
tween form  and  bank  will  hold  it  to  street  line.    To 
keep  from  spreading  below,  near  the  middle  place 
two  blocks,  one  on  each  side.    When  the  form  is  filled 
and  well  rammed  and  the  top  floated  even  and  edges 
rounded  with  an  edger,  the  top  strips  and  the  side 
blocking  is  removed,  the  form  spreads  at  open  end, 
and  with  one  man  in  trench  at  closed  end  and  one  at 
each  side  at  open  end,  the  form  is  slipped  along  the 
trench  for  the  next  block.     In  making  the  blocks  8 
feet  long  the  form  will  lap  on  the  last  stone  Vz  foot. 
When  trued  to   line   and   before   again   filling,   put 
paper  against  the  upright  joint,  or  better,  plaster 
with  clay  x/4  inch;  this  joint  allows  slight  adjustment 
in   weather  conditions   without  breaking  the   stone. 
If  doweling  is  desired  drive  iron  pin  %  inch  thick 
and  4  inches  long  half  way  into  the  last  block  and 
6  inches  from  top  down.     Now  proceed  as  before, 
Batching  that  the  exposed  surface  is  compact.     In 
the  composition  of  the  concrete  for  curbing  it  would 
be  an  economy  in  cost  without  any  sacrifice  in  qual- 
ity if  two  mixes  of  concrete  were  carried.     The  bot- 
tom could  be  coarse,  with  a  fine  concrete  top  in  which 
the  top  can  be  finished  without  mortar;  not  more 
than  1  foot  of  the  top  will  be  exposed.     For  bot- 
tom take,  cement,  1;   sand,  3;  aggregate,  4  parts. 
After  24  hours  the  work  can  be  carefully  filled  but 
should  not  be  tamped  much  before  6  days.     The  top 
should  be  covered  and  kept  wet  for  6  days. 

Posts. 

Hitching  posts,  where  desired,  can  be  continued 
from  the  curbing  in  the  following  way:  Take 
wrought  iron  &  x  %  meh  and  9  feet  long;  this 
should  be  twisted  or  crimped;  double  it  over  in  the 
center  so  as  to  be  about  3  inches  across  at  closed  or 
55 


doubled  end  and  about  6  inches  at  open  end;  set  open 
end  down  into  the  curb  form,  with  the  top  projecting 
perpedicularly  above  the  curb,  about  2^  feet;  these 
could  be  placed  at  regular  intervals  or  where  posts 
were  desired  and  afterwards  with  a  post  form  most 
desirable  for  this  work;  the  posts  could  be  easily 
built  from  the  curb  up.  These  posts  could  be  cast 
with  2-inch  holes  through  the  top;  this  should  ex- 
tend between  the  irons,  or  instead,  a  long  link  with 
ring  might  be  bedded  into  the  side  or  top  as  desired. 
These  irons  fastened  or  bedded  in  the  curb  and  ex- 
tending into  the  post  would  make  an  indestructible 
post,  well  out  of  the  way  and  at  the  proper  place. 
At  this  point  we  wish  to  say  that  heavy  posts  either 
for  hitching  or  gates  for  mammoth  resident  drives 
in  the  city,  cemetery  and  park  entrances,  with  arched 
columns  connecting  them  as  desired,  are  built  of 
reinforced  concrete;  this  can  be  made  with  elaborate 
moldings  and  panels  and  at  a  very  low  cost  as  com- 
pared with  stone  in  similar  construction,  and  supe- 
rior in  quality  in  every  way.  Molds  of  this  char- 
acter would  form  an  item  in  the  cost,  but  if  well 
made  and  carefully  handled,  could  be  used  a  number 
of  times,  thus  reducing  the  first  cost.  In  such  work 
the  excavation  is  made  as  for  other  work,  and  in 
depth  must  correspond  to  the  top  structure;  instead 
of  placing  porous  foundation,  the  concrete  is  begun 
at  the  bottom,  encasing  the  reinforcing  metal  near 
the  bottom.  The  kind  of  metal  used  and  the  method 
of  placing  must  be  regulated  by  the  superstructure. 
After  the  molds  are  removed  the  surface  is  moist- 
ened and  paste  mortar  applied  with  brush  and  with 
hand  polisher  rubbed  into  the  surface.  After  the 
work  is  dried,  or  say  24  hours,  the  surface  is  again 
washed  and  cleaned;  this  now  has  the  appearance  of 
a  hand  rubbed  stone  surface.  The  molds  are  only 
required  from  the  grade  up;  the  excavation  is  built 
up  against  the  bank  or  sides. 
Cistern. 

The  concrete  method  of  cistern  construction  now 
coming  into  use  promises  some  points  of  excellence, 
but  with  cumbrous  and  costly  forms  the  work  is 
greatly  hindered,  or  at  least  confined  into  the  hands 

*  56 


of  a  few  operators.  The  best  and  strongest  shape 
for  a  cistern  is  the  circular  or  jug  shape  and  is  the 
most  difficult  to  arrange  for  the  forms.  These  are 
built  in  sections,  small  enough  that  they  can  be  re- 
moved from  the  top  opening  when  through.  They 
should  be  made  to  set  together  and  bind  without 
any  nailing;  also  that  they  can  be  removed  without 
crowding  or  hammering;  are  most  usually  carried 
to  height  as  the  work  progresses.  Where  the  size 
of  the  form  is  known  the  excavation  must  be  made 
to  suit,  and  with  care  in  excavation  much  waste  in 
material  can  often  be  saved.  When  excavated  and 
the  form  placed  there  should  be  4  or  5  inches  space 
between  it  and  the  bank.  No  metal  reinforcement 
is  needed  in  these  circular  walls.  '  The  concrete  for 
these  should  be,  cement,  1;  sand,  3;  fine  aggregate, 
3  to  4  parts.  After  a  few  days  the  form  is  removed, 
the  sides  plastered  with  mortar,  cement,  1;  sand,  2 
or  3;  the  bottom  is  placed  last,  and  should  be  dug 
concave  (hollowed  out)  for  strength  and  conven- 
ience in  pumping  the  water  nearly  all  out,  for  clean- 
ing, etc.  Place  concrete  over  bed  3  or  4  inches  thick; 
plaster  this,  and  the  interior  is  done.  The  inlet  and 
outlet  being  placed  into  side  wall  as  this  was  carried 
up.  The  top  arch  represents  the  shape  of  a  jug  and 
is  carried  continuously  from  the  side  wall  to  the 
opening;  this  should  be  20  inches  in  diameter  for 
common  sized  cistern.  This  opening  or  neck  is  contin- 
ued to  grade  line  and  should  be  about  18  inches  high. 
The  rectangular  cistern  is  best  suited  to  easy 
form  constructions.  Say  12  feet  long,  5  feet  wide 
and  6  or  8  feet  high,  for  common  house  use,  would 
be  a  fair  size.  With  5  pairs  of  uprights  stayed 
across  with  stiff  strips  and  wood  screws  5  feet  from 
outside  to  outside,  one  pair  at  each  end,  one  in  the 
middle,  and  one  each  between  middle  and  end.  This 
will  leave  3  feet  between  uprights  on  sides,  and  on 
the  ends  another  could  be  placed  in  the  middle  stayed 
to  a  stake  in  the  ground.  Thus  it  will  be  seen  that 
boards  in  lengths  of  2%,  3,  5  and  6  feet  could  be 
used,  but  should  all  be  of  one  thickness  and  width. 
The  boards  are  placed  against  the  uprights,  as  the 
wall  is  carried  up;  when  the  top  of  the  uprights  is 
**  57 


reached  arch  circles  or  segments  are  supported  on 
the  uprights,  these  segments  have  a  rise  of  1  foot  in 
the  space  of  5  feet.  These  are  fastened  to  the  up- 
rights so  as  to  be  easily  removed  and  so  that  the 
arch  will  take  its  bearing  on  the  walls ;  over  this  nar- 
row boards  are  spread,  say  6  inches  wide;  now  the 
concrete  is  placed  on  them  and  must  be  rather  wet 
since  not  much  tamping  can  be  done  on  these  light 
boards.  This  arch  should  be  5  inches  thick  and 
sides  4  inches;  these  cisterns  usually  have  a  filter 
wall  near  the  middle  made  of  porous  brick,  and  for 
this  reason  a  man-hole  will  be  left  at  each  end  of 
about  20  inches  in  diameter;  these  are  built  with 
two  heavy  sheet  iron  forms,  which  are  so  made  that 
they  can  be  slightly  expanded  or  contracted,  in  order 
to  remove.  One  is  used  on  the  inside,  and  the  other 
on  the  outside,  with  4  inches  space  between,  with 
these  man-holes  are  carried  to  the  grade  line.  After 
a  few  dLays  the  form  is  removed,  the  interior  plas- 
tered, cross  filter  wall  laid.  This  wall  is  a  single 
or  double  brick  wall  4  or  8  inches  thick,  bedded  in 
cement  mortar  carefully  laid  so  the  water  in  pass- 
ing from  inlet  part  into  the  outlet  part,  or  pump 
part,  must  pass  through  the  brick.  The  wall  should 
be  built  slightly  convex  toward  inlet  part,  so  that 
in  heavy  rains  when  the  water  would  set  highest  in 
the  inlet  part  it  would  not  shove  the  wall  over.  The 
filter  wall  must  be  carried  a  little  higher  than  the 
outlet  tile.  The  outlet  and  inlet  tiles  should  both 
be  built  into  the  inlet  part;  also  this  filter  wall  must 
never  be  built  on  the  ground  or  the  cistern  would 
leak  through  into  the  ground.  The  bottom  is  con- 
cave, with  pump  part  of  cistern  slightly  deepest. 
Concrete  2  inches  deep  is  placed  over  this  and  plas- 
tered; this  is  done  last,  except  the  small  strip  where 
the  filter  wall  is  set.  In  larger  work  of  this  char- 
acter when  the  span  of  the  arch  is  longer,  expanded 
metal  should  be  incorporated  in  the  arch,  and  when 
filter  wall  is  not  used  inside,  the  long  side  walls 
should  be  5  inches  thick. 

Reservoirs 

are  usually  large  storage  receptacles  for  water 
variously  used.  City  water  works,  for  irrigation  and 


large  factory  purposes,  etc.  Reservoirs  are  usually 
round,  sometimes  entirely  buried  in  the  earth;  some 
others  partly,  while  some  are  only  set  deep  enough 
for  solid  and  uniform  foundation. 

Their  construction  in  whatever  position  is  much 
the  same,  only  the  pressure  of  the  water  is  counter- 
acted when  filled  against  the.  outside,  and  that  the 
pressure  decreases  from  the  bottom  to  top.  The 
diameter  of  a  reservoir  has  little  to  do  with  the  ex- 
panding power,  but  height  has  everything.  The  ex- 
cavation is  first  made  and  when  deep  enough  the 
bottom  must  be  concave,  with  the  sharpest  angle 
near  the  wall,  which  partly  takes  its  bearing  on  the 
bottom,  distributing  this  bearing  from  circumference 
to  center;  though  the  circular  wall  is  usually  built 
first,  there  is  a  reinforced  collar  or  projection  built 
on  the  inside  and  about  8  or  10  inches  from  the  bot- 
tom, where  the  wall  and  bottom  connect.  First  a 
circular  form  is  built  for  the  inside;  say  the  reser- 
voir is  to  be  100  feet  in  diameter  and  14  feet  high,  in 
this  case  we  would  take  16-foot  2x4  scantling,  bury 
the  bottom  1  foot  in  the  ground,  set  them  perfectly 
perpendicular,  brace  near  middle  and  top  securely 
by  nailing  bottom  of  brace  strips  to  solid  stake  well 
driven  into  the  ground;  sheet  this  half  way  up  with 
plain  surfaced  sheeting  4  or  6  inches  wide;  now  place 
outside  studding  in  same  way,  leaving  the  space  for 
the  wall  between  the  sheeting,  say  10  inches.  The 
outside  studding  only  need  be  braced  in  middle,  when 
the  wall  is  carried  to  this  point,  cross  pieces  are 
nailed  across  the  top  to  hold  the  outside  in  place. 
Only  sheet  outside  2  feet  high;  clean  the  wall  space 
ready  for  concrete;  place  6  or  8  inches  and  thor- 
oughly tamp.  The  reinforcing  is  now  placed,  and 
with  some  engineers  expanded  metal  is  used,  carried 
continuously  from  bottom  to  top,  and  in  about  the 
middle  of  the  wall,  usually  using  lighter  sizes  toward 
the  top.  Others  use  wrought  iron  twisted  rods  sus- 
pended alternately  from  side  to  side;  also  perpen- 
dicular irons  at  regular  intervals.  But  in  either  case 
care  must  be  taken  that  the  joints  in  the  reinforc- 
ing are  well  broken  and  lap  at  least  6  inches,  directly 
at  this  point  where  the  bottom  and  wall  are  joined 
59 


it  is  most  essential  that  strong  lateral  bonding 
should  be  secured,  for  in  addition  to  the  great  water 
pressure  at  the  base  the  deflection  caused  by  the 
bearing  of  the  wall  on  the  concave  bottom  would 
amount  to  a  considerable  strain,  which  must  be  over- 
come. But  on  work  of  such  magnitude  there  must 
be  a  supervising  engineer,  whose  business  it  is  to 
direct  as  to  the  kind  and  method  of  reinforcing.  I 
only  wish  in  the  space  of  this  book  to  give  general 
details  of  methods,  so  that  the  lay  workman  can 
come  to  it  with  a  little  more  aptness.  The  concrete 
used  among  this  reinforcing  must  be  wet  even  to 
quaking  and  should  not  contain  too  coarse  materials, 
cement,  1;  sand,  3;  fine  aggregate,  2  or  3  parts;  this 
io  carefully  tamped  about  tKe  metal  so  that  it  is 
thoroughly  and  tightly  encased  by  the  concrete.  As 
this  is  carried  up  the  sheeting  is  continued;  the  top 
must  be  level.  Ordinarily  the  sheeting  can  be  re- 
moved when  completed;  wet  sides,  and  plaster  in  and 
outside  with  mortar  of  cement,  1;  sand,  fine,  2.  The 
bottom  is  now  placed,  usually  there  is  an  opening 
left  in  the  side  through  which  materials  are  taken 
which  are  afterwards  closed.  'The  bottom  should 
be  6  or  8  inches  thick,  reinforced  by  light  expanded 
metal  sheets,  laid  about  the  middle  of  the  concrete, 
since  the  pressure  is  about  the  same.  The  bottom 
is  also  plastered  same  as  sides.  Large  vats,  stand- 
pipes  and  many  other  similar  structures  are  made 
in  the  same  way. 

Grave  Vaults. 

Of  the  rapidly  increasing  adoption  of  this  method 
of  burial  it  is  not  our  purpose  to  speak.  Simply  as 
to  the  best  plans  of  construction. 

When  the  size  of  the  casket  for  which  the  vault 
is  desired  is  known,  a  form  of  suitable  size  is 
selected  or  made.  This,  in  size  and  shape,  would 
correspond  to  the  "rough  box"  usually  used  over  the 
casket.  The  form  will  be  built  similar  to  these,  only 
that  there  is  no  bottom  or  top,  and  instead  of  nail- 
ing them  as  the  ''rough  box"  is,  the  strips  in  the 
corners  of  the  form  are  held  in  place  by  wood  screws, 
which  when  removed,  will  allow  the  ends  to  be 
slipped  in,  and  afterwards  the  sides.  The  ends  of 
60 


these  forms  should  be  sawed  beveling  so  that  when 
one  end  is  drawn  in  it  does  not  bind  or  crowd  on  the 
other  corner,  but  at  once  becomes  loose.  Dig  grave 
large  enough  so  that  when  form  is  placed  there  will 
be  5  inches  room  between  form  and  bank  for  con- 
crete. Before  the  form  is  set  in  place,  put  in  bot- 
tom of  concrete  3  inches  thick.  Place  form  and 
secure  center  of  sides  by  cross  stay;  now  fill  con- 
crete between  form  and  bank,  and  tamp  well;  when 
carried  to  the  top  of  form,  even  the  top,  and  in  two 
hours  of  drying  weather  the  form  can  be  removed. 
Plaster  sides  first,  finishing  with  small  wooden  float; 
now  finish  bottom  in  the  same  way. 

The  proportion  of  concrete  for  this  work  should 
be,  cement,  1;  sand,  3;  aggregate,  4.  When  ready 
for  burial  place  drapery  into  the  bottom  of  vault  and 
extending  up  one  end.  When  casket  is  placed  fold 
the  drapery  up  along  and  back  over  casket.  Over 
the  top  of  this  place  arch  form;  this  must  be  tight 
so  that  nothing  will  drop  into  vault.  The  arch  form 
should  have  circular  top  of  about  4  inches  rise  in  the 
middle,  and  is  made  of  narrow  strips  of  surfaced 
boards  nailed  on  the  arch  lintels,  one  at  each  end, 
and  the  other  in  the  middle,  and  the  whole  must  be 
large  enough,  so  that  it  will  rest  from  1  to  l1/^  inches 
on  the  end  and  side  walls. 

The  concrete  is  now  placed  on  this  form  4  or  5 
inches  thick;  this  cannot  be  tamped  and  therefore 
must  be  mixed  rather  wet,  but  not  so  wet  as  to  drip; 
in  this  way  it  can  be  worked  down  compact  with 
trowel.  With  a  little  care  in  throwing  on  the  first 
ground  the  grave  can  be  filled  at  once.  This  vault  is 
water  tight,  impenetrable,  constant  as  stone,  and 
will  cost  in  the  average  location  about  $24.  The 
shape  and  character  of  the  vault  can  be  varied  from 
the  simple  vault  described,  to  the  most  artistic,  with 
panels,  moldings,  etc.,  in  some  cases  extending  above 
the  ground,  covered  with  artistic  coping,  surmounted 
with  statuary,  etc.  We  will  give  a  brief  description 
of  a  still  more  simple  method,  coming  into  extensive 
use  and  in  every  way  as  serviceable  as  the  most  ex- 
pensive. For  this  dig  grave  same  as  in  other  de- 
scribed, put  in  bottom  of  concrete  3  inches  thick,  on 
61 


this  set  the  "rough  box;"  stay  center  of  "rough  box" 
so  that  the  sides  will  not  crowd  in  in  tamping;  now 
place  lid  on  box  to  keep  box  clean,  and  place  con- 
crete in  small  layers,  tamping  solid.  Since  this  is 
not  plastered  on  the  inside,  extra  tamping  and  fine 
concrete  must  make  it  dense  and  impervious  to 
water.  Use,  cement,  1;  sand,  3;  fine  aggregate,  3; 
when  completed  remove  lid  and  place  drapery;  when 
casket  is  lowered  into  place  fold  drapery  back  over 
casket,  place  lid  in  position  and  over  this  place 
rather  wet  concrete  5  or  6  inches  thick.  This  is 
a  most  simple  method;  can  be  placed  in  all  kinds  of 
Weather  and  at  short  notice,  and  for  all  purposes  of 
a  vault  is  unexcelled. 

Culverts. 

These  are  coming  into  use  in  all  sections  of  the 
country,  in  which  well  advanced  ideas  in  road  con- 
struction are  prevalent.  They  are  cheaper  by  from  25 
to  50  per  cent  than  any  other  method  of  equal  merit. 

By  the  proper  reinforcing  of  the  concrete  with 
metal  much  is  saved  in  the  cost,  and  at  the  same 
time  much  is  added  to  the  strength  and  durability  as 
compared  to  the  old  method  of  "Ordinary  Concrete." 

In  the  space  of  this  little  book  we  can  only  give 
fundamental  methods;  these  must  be  varied  to  each 
particular  job. 

A  most  substantial  culvert  is  built  in  the  follow- 
ing way:  Excavate  safely  below  the  erosion  of  the 
stream,  and  unless  on  stone  it  is  usually  better  to 
use  footings  for  the  trench  wall  (see  footings);  also 
excavate,  etc.,  the  same  for  the  wing  wall.  These 
are  the  walls  that  project  back  from  the  bench 
walls,  at  the  most  suitable  angle,  and  which  are  ex- 
tended to  the  top  of  culvert  arch  or  even  above. 
They  serve  the  double  purpose  of  holding  the  road- 
bed in  place  and  securing  against  washing  of  road- 
bed back  of  wall;  they  also  add  strength  to  the 
whole  structure. 

When  the  excavation  is  done  and  the  footing 
placed,  the  forms  are  now  set  in  position.  For  illus- 
tration we  shall  suppose  this  culvert  to  have  a  12- 
foot  waterway  and  24-foot  roadway.  Then  in  this 
case  by  using  expanded  metal  in  walls  and  arch  we 
62 


conclude  that  an  8-inch  wall  is  heavy  enough;  this 
we  will  strengthen  by  2  pilasters  on  the  back  side 
of  each  bench  wall,  dividing  the  space  of  each  bench 
wall  into  8-foot  sections;  also  another  pilaster  at  the 
end  of  each  wing,  making  in  all  for  this  culvert,  8 
pilasters;  these  should  measure  at  the  base  10x16 
inches  clear  of  wall  and  stand  with  narrow  edge  to 
the  wall,  their  width  the  16-inch  way  should  be  re- 
duced to  6  inches  at  the  top.  In  this  case  when  the 
bench  walls  are  3  feet  high,  the  arch  is  now  placed, 
taking  its  bearing  on  the  bench  walls. 

The  arch  may  be  a  segment  arch  or  a  semi-circle 
arch;  this  must  always  depend  on  the  depth  of  the 
stream  from  the  roadway,  and  it  must  not  be  over- 
looked that  in  segment  arches  the  bench  walls  must 
be  constructed,  to  hold  in  addition  to  the  perpen- 
dicular weight  of  arch  and  earth  upon  it,  also  a  great 
lateral  or  deflected  strain  towards  the  bank.  This 
must  be  overcome  in  the  building  of  the  bench  walls, 
which  would  require  greater  thickness  of  these  walls, 
or  an  inclination  towards  the  arch  would  support  the 
strain.  The  result  of  this  deflection  on  the  walls  by 
the  arch  increase  with  the  span  of  the  arch.  It 
would  also  be  largely  increased  by  every  degree  of 
flattening  of  the  arch.  The  wall  described  would  be 
suitable  for  a  semi-circle  arch  or  a  segment  arch  of 
not  less  than  4  feet  rise  in  center. 

In  building  up  the  wall  when  the  forms  are 
placed,  at  once  insert  the  expanded  metal,  leaving 
room  on  the  face  side  for  3  inches  of  concrete  and  on 
back  side  for  5  inches.  The  tops  of  these  metal 
sheets  should  project  above  the  top  of  the  bench 
wall  6  inches,  from  which  point  they  are  carried  into 
the  arch,  with  the  arch  metal.  The  wings  are  rein- 
forced their  whole  height  the  same  as  bench  walls  and 
should  connect  with  the  arch  metal  when  they  join. 

When  ready  for  the  arch,  place  arch  lintels  at 
suitable  distances  to  support  the  weight  of  the  arch; 
over  these  place  2x4  scantlings ;  this  will  form 
under  face  of  arch;  on  this  place  concrete,  begin- 
ning near  the  bench  walls  place  3  inches  thick  for  a 
convenient  space;  on  this  place  the  expanded  metal, 
and  over  this  again  place  5  inches  of  concrete. 
63 


The  concrete  for  this  work  should  be  rather  wet 
so  that  it  will  pack  about  and  through  the  meshes 
of  the  metal  in  one  continuous  mass.  The  arch  lin- 
tels should  be  set  on  wedges,  which  when,  the  con- 
crete is  well  set  may  be  driven  back  to  loosen  the 
false  work,  so  as  not  to  crowd  or  break  the  arch. 

The  end  or  wing  walls  are  carried  to  the  height 
desired  and  could  be  finished  with  a  coping  top 
course,  the  ends  plastered  and  blocked  off  into  nicely 
broken  stone  work.  The  arch  and  wall  should  be 
seasoned,  for  which  see  "Concrete." 

Another  method  of  small  culvert  construction 
when  water  way  required  is  not  over  6  feet  in  diam- 
eter, is  as  follows:  Upon  excavated  bed  of  the  de- 
sired height,  place  from  2  to  4  inches  of  concrete, 
on  this  place  expanded  metal  about  18  inches  wide, 
over  top  place  2  inches  more  of  concrete.  On  this 
lay  collapsible  circular  form  the  size  desired,  build 
around  this  form  shell  of  concrete  with  expanded 
metal  contained  in  middle,  the  thickness  of  shell 
would  vary  with  size,  but  would  not  need  be  over 
6  inches  for  the  most  exacting  requirements. 

The  ends  of  this  circular  shell  could  terminate 
in  end  retaining  walls.  Wash  aprons  or  any  other 
construction  most  suitable  to  overcome  wash  of 
stream. 

Steps 

are  of  two  kinds;  those  cast  in  one  solid  piece  of  con- 
crete— Steps  and  Sides  or  Housings. 

Steps  cast  in  separate  pieces  and  afterward 
placed  in  position  are  described  under  "Heavy 
Blocks"  in  this  Part.  When  the  place  for  the  steps 
is  known,  ascertain  the  entire  height  or  rise,  divide 
this  into  steps  of  equal  height,  not  less  than  6  inches 
nor  more  than  8  inches;  next  in  the  same  way  de- 
termine the  width  of  the  tread,  like  the  height:  their 
width  must  be  the  same,  not  less  than  10' inches  nor 
more  than  14  inches  unless  made  wide  enough  so 
that  one  or  more  steps  can  be  taken  on  the  tread,  as 
30  inches,  etc.  Steps  with  housings  or  closed  ends 
should  always  be  built  wide,  even  wider  than  walk 
from  which  they  lead  so  as  not  to  look  cramped. 
When  all  this  is  determined,  a  form  is  built  to  suit 
64 


the  requirement. 

In  the  cities  there  are  regular  form  builders, 
elsewhere  a  carpenter  or  mason,  handy  at  such  work 
could  build  a  very  good  one.  In  this  work  we  can- 
not give  details  for  the  building  of  these  forms,  sim- 
ply to  say  a  few  things  common  to  all  form  or 
molds.  Upon  the  form  will  depend  the  appearance, 
and  very  largely  the  strength  of  the  step. 

First  the  form  in  no  place  should  cut  off  propor- 
tionate strength  of  body  work.  The  top  should  be 
open  at  all  points  possible,  so  the  concrete  can  be 
well  rammed  into  place;  the  bottom  is  also  open 
only  where  necessary  to  bind  together  with  light 
strips,  for  strength  and  holding  form  stiff. 

With  the  judicious  use  of  some  moldings  and 
panels  the  step  will  not  be  strong  but  can  be  made 
artistic.  Molds  are  made  with  surfaced  lumber,  put 
together  with  wood  screws,  which  can  be  easily  re- 
moved when  through  and  stored  for  another  occa- 
sion. These  molds  cost  from  3  to  15  dollars,  yet  the 
step  when  completed  would  not  cost  one-half  as  much 
as  a  cut  stone  step  of  similar  design,  and  if  skillfully 
done  will  be  better  in  every  way  than  a  stone  step. 

The  form  ready,  the  next  thing  to  do  is  to  have  a 
thoroughly  good  bed  prepared  to  build  on;  this  in 
clay  soil  should  be  18  inches  deep;  a  little  wider  and 
longer  than  step;  must  have  outlet  or  drain  to  this 
porous  pit,  so  no  water  will  set  in  foundation.  Now 
place  form  level  and  true  as  you  would  have  the 
steps  be;  with  sprinkling  can  thoroughly  wet  the 
form,  so  that  it  is  thoroughly  expanded  before  the 
concrete  is  placed  in.  The  concrete  for  this,  in  order 
to  give  it  nice  and  compact  face  must  not  contain 
coarse  aggregate;  surfaces  patched  always  show  and 
should  be  avoided.  Cement,  1;  sand,  2%;  fine  peb- 
bles, 3  parts.  (See  "Mixing  of  Concrete.") 

This  proportion  of  concrete  13  given  with  a  vi?*v 
to  a  regular  and  well  filled  face.  With  a  little  care  in 
placing,  the  body  woik  of  the  step  could  be  made  of 
coarser  aggregate  a):  a  considerable  saving-  of  cost 
in  materials.  The  concrete  is  placed  into  the  form 
a  little  at  a  time  and  well  tamped,  with  care  to  avoid 
air  spaces  and  rough  or  loose  places  in  the  face  of 
65 


the  work.  This  completed  and  the  top  surfaces  of 
steps  and  housing  smooth,  with  sharp  edges  rounded 
with  sidewalk  edger  or  trowel,  the  work  is  com- 
plete, ready  to  season  and  remove  the  form. 

In  most  cases  it  is  best  to  remove  the  form  after 
24  hours  and  before  seasoning. 

Sometimes  when  the  forms  are  not  properly  ex- 
panded before  they  are  used,  if  left  on  while  season- 
ing the  work  the  forms  expand  and  chip  the  edges 
of  panels  and  moldings. 

Steps  as  described  have  two  uses  generally: 
First,  that  of  a  step  against  a  bank,  such  as  a  step 
leading  .from  the  sidewalk  upon  the  yard  walk,  etc. 
In  this  case  the  bed  is  prepared  in  line  with  the 
grade  but  enough  deeper  so  as  to  contain  the  body  of 
the  step,  and  should  be  heavy  enough  at  the  back  or 
lower  edge  of  each  step  so  that  no  checks  will  ap- 
pear. This  is  built  up  in  solid  body  from  the  founda- 
tion. The  form  must  be  built  for  this  use  of  a  step. 

Second:  This  use  is  usually  as  leading  from  a 
porch  down  into  the  walk  or  grade  line.  These  are 
set  on  the  level  and  the  form  is  built  with  the  end 
housings  extending  down  to  the  level  or  grade. 
When  the  steps  are  more  than  6  feet  long  they 
should  have  a  blind  housing  underneath  in  middle  to 
support  the  step.  The  forms  are  so  constructed  for 
this  use  of  a  step  that  the  space  underneath  and  be- 
tween the  housings  are  left  open,  and  since  these 
steps  are  tamped  on  the  hollow  form  below  they 
should  be  built  with  rather  wet  concrete  so  they  may 
become  compact,  with  this  disadvantage  of  tamping. 

It  should  be  remembered  that  no  steps  can  be 
built  to  look  well  without  some  form  of  a  molded 
projection  extending  forward  from  the  top  of  the 
step.  This  can  still  be  heightened  by  a  narrow  panel 
beneath  the  molding  and  on  the  front  face  of  the 
step.  The  sides  or  housings  must  be  heavy  enough 
to  look  proportionate,  and  in  addition  to  a  projec- 
tion representing  a  molded  coping,  they  can  have 
panels  either  molded  or  plain.  It  is  not  at  all  diffi- 
cult to  prepare  the  molds  for  these  designs,  when 
it  is  remembered  the  face  of  all  moldings  and  trim- 
mings represent  reverse  form  of  the  cast  product. 
66 


This  molding  must  be  so  manipulated  as  to  give 
a  pleasing  effect  to  the  eye.  Corner  molding^  can 
be  so  placed  into  the  corners  that  the  sharp  edges 
can  be  avoided,  etc. 

Portable  Concrete  Cast   Masonry. 

Under  this  division  are  included  cast  products, 
built  at  factories  for  this  purpose,  and  which  are 
usually  supplied  to  the  trade  in  a  commercial  way. 
The  many  different  wares  produced  in  this  line  are 
usually  made  by  machine  mold,  many  of  which  are 
secured  by  patents.  All  cities  and  many  villages 
have  one  or  more  of  these  factories.  Their  products 
cover  a  large  and  useful  field,  with  an  ever  increas- 
ing demand  and  variation. 

While  the  most  of  these  molds  are  metal,  some 
special  or  irregular  products  are  frequently  made 
with  the  use  of  wooden  forms.  At  this  point  we 
wish  to  impress  the  importance  of  thorough  expan- 
sion, by  thoroughly  wetting  the  forms  before  they 
are  used.  There  are  at  least  two  reasons  for  this 
which  should  be  known.  First,  the  dry  surface  of 
the  wood  absorbs  the  moisture  of  the  concrete  next 
the  face  and  arrests  a  chemical  process  in  the  hard- 
ening which  leaves  the  surface  of  the  product  loose 
and  pliable.  Second,  the  form  becoming  moist  from 
the  concrete,  expands,  and  when  the  work  is  partly  or 
wholly  set  crowds  shoulders  or  panels,  and  other 
irregular  surfaces,  straining  them  open  and  impair- 
ing their  value.  The  importance  of  this,  however, 
attaches  mostly  when  the  wares  are  seasoned  in  the 
mold,  for  when  molds  are  at  once  emptied  this  can 
not  matter. 

Concretes  for  these  products  are  usually  com- 
posed of  cement,  1;  sand,  (coarse  and  fine  mixed),  3 
to  4  parts.  The  coarser  products  and  such  as  have 
extra  facing  could  be  made  cheaper  and  even 
stronger  by  adding  aggregate  (not  too  coarse)  to 
the  above  from  3  to  6  parts.  For  some  work,  such  as 
cast  statuary,  cement  and  sand  of  equal  parts  are 
used.  Sand  for  this  work  should  be  fine.  The  pro- 
portions must  always  be  well  mixed  dry,  then  grad- 
ually sprinkled,  and  at  the  same  time  thoroughly 
worked  over.  Long  and  thorough  working  of  concrete 
07 


and  mortar  have  shown  by  briquet  tests  increases  of 
from  30  to  50  per  cent  in  strength,  so  that  nothing 
should  be  spared  in  this  line  if  it  is  desired  to  ob- 
tain the  best  results. 

Concrete  for  this  work  should  be  mixed  wet 
enough  to  work  compact,  but  should  not  quake  in 
working  or  settle  out  of  true  when  removed  from 
the  mold.  We  think  that  it  is  the  practice  in  quick 
molded  work  to  mix  rather  dry,  since  this  allows 
the  casting  to  come  from  the  mold  with  well  out- 
lined face,  sets  up  well  on  pallet  and  requires  less 
material  because  less  dense.  While  passable  for 
light  work,  yet  under  tests  this  would  show  inferior 
tensile  and  compressing  strength  as  compared  with 
the  slightly  wetter. 

Building  Blocks. 

These  blocks  are  classified  as  of  two  kinds.  The 
small  and  hollow  blocks  usually  for  light  uses,  and 
solid  blocks  mostly  heavy.  Of  these  we  shall  speak 
first,  because  of  their  size  and  use  they  require  a 
different  composition  of  concrete  from  most  wares 
in  this  chapter.  Also  they  are  usually  cast,  conven- 
ient to  the  work  on  which  they  are  used,  and  con- 
sequently would  not  come  under  the  commercial 
qualifications  applicable  to  most  products  under  this 
division. 

The  composition  of  these  blocks  is  .cement,  1; 
sand,  2  Ms;  hard  aggregate,  4  to  6  parts.  This  is 
varied  according  to  the  character  of  the  work  on 
which  the  blocks  are  used,  and  the  quality  of  the 
sand  and  aggregate  used  in  the  composition.  These 
blocks  are  usually  large,  sometimes  weighing  sev- 
eral tons,  and  represent  a  line  of  work  requiring 
great  strength.  Custom  houses,  fortifications,  docks, 
light  houses,  reservoirs,  dams,  canal  locks,  and  many 
other  government,  railroad  and  corporation  construc- 
tion. The  blocks  are  cast  in  metal  forms,  are 
usually  tamped  by  power  pressure,  when  removed 
from  the  form  are  seasoned  (kept  wet  and  covered 
from  currents  of  air).  In  some  cases,  after  a  few 
days,  while  wet,  the  faces  are  buttered  (mortar  of 
cement,  1  part;  granite  dust  or  sharp  fine  sand,  2 
parts);  this  is  applied  with  brush  and  thoroughly 
68 


rubbed    into    the    face    surface,    making    the    face 
smooth,  impervious  to  water,  and  uniform  in  color. 

These  blocks  are  superior  to  stone  in  either  air 
or  submerged  work,  and  are  used  over  the  entire 
civilized  world.  Similar  to  these  blocks,  but  fre- 
quently with  wooden  molds,  steps  large  or  small, 
belt  courses,  massive  columns,  wall  copings,  engine 
beds,  well  tops,  etc.,  are  constructed. 
Hollow  Blocks. 

These  are  mostly  used  in  buildings,  large  or 
small,  and  are  made  of  every  conceivable  shape.  The 
metal  machines  for  their  construction  are  plentiful 
and  are  usually  secured  by  patents,  each  claiming 
for  their  product  superiority  over  others.  The  yards 
or  factories  building  them  are  found  in  almost  every 
village  in  our  country. 

In  this  particular  line  (hollow  blocks)  the  United 
States  clearly  takes  the  lead.  The  use  of  these 
blocks  has  rapidly  found  its  way  into  building  con- 
struction wherever  modern  engineering  has  been 
employed.  They  are  cheaper,  less  easily  penetrated 
by  water,  heat  or  cold,  than  solid  blocks.  They  are 
made  with  rock  face,  smooth  face,  or  ornamental 
face,  as  desired.  In  city  construction  they  promise 
to  entirely  supplant  stone  because  better  and 
cheaper,  and  because  of  appearance  have  already 
largely  taken  the  place  of  brick  in  face  work.  The 
rock  face  varieties  in  many  cases  not  being  easily 
detected  from  natural  face  stone. 

Many  of  the  block  machines  are  so  constructed 
that  a  thin  facing  is  built  into  the  block  face.  This 
is  usually  denser  and  in  some  cases  is  colored  in 
imitation  to  the  many  different  colored  stone.  Most 
of  these  block  machines  make  many  different  sized 
block,  in  fact  anything  needed  in  the  construction 
of  a  building:  light  and  heavy  wall  blocks,  different 
lengths  and  heights,  corners,  jambs,  blocks  with 
joist  spaces,  sills,  lintels,  chimney  blocks  and  tops, 
water  tables,  belt  courses,  different  designed  faces,  etc. 

All  other  things  being  equal,  the  machine  con- 
structed to  give  strong  power  pressure  to  the  con- 
crete when  placed  into  the  mold,  is  superior  to  the 
hand  tamped  block  because  the  latter  are  sometimes 


insufficiently  or  unevenly  tamped,  while  the  former 
would  be  evenly  strong  in  all  parts  of  the  same 
block,  and  one  block  the  same  as  another.  This  essen- 
tial is  required  by  all  builders,  but  it  is  evident  that 
by  careless  manipulation  it  is  not  always  attained. 

Also  machines  that  allow  of  building  the  web  and 
body  of  the  block  from  coarse  concrete,  and  at  the 
.same  time,  building  into  the  face  one  inch  or  so  of 
face  concrete  (finer  and  richer),  are  considered  supe- 
rior to  others  that  will  not  allow  of  this.  This 
cheapens  the  block  without  any  diminution  in  qual- 
ity, while  the  fine  rich  face  gives  it  density,  which 
secures  for  it  impenetrability  to  water  and  beauty  of 
face.  It  is  objected  by  some  that  this  veneering 
of  the  face  will  flake  off.  This,  however,  is  never 
the  case  where  the  body  and  face  of  the  block  are 
built  up  continuously  and  at  one  molding,  but  if  faced 
afterward,  the  objection  may  be  sustained. 

There  is  one  serious  objection  to  the  concrete 
block  wall  which  workmen  and  architects  have 
worked  to  overcome,  and  even  at  this  time  not  en- 
tirely successfully.  This  is  the  penetration  of  walls 
by  dampness  and  water,  called  "Capillary  Attrac- 
tion." Continuous  rain  against  many  of  these  hol- 
low walls  will  drip  from  the  surface  on  the  inside. 
Though  hollow  this  passes  through  the  web  or 
bonding,  and  it  may  be  said  that  for  the  first  ^  few 
years  of  the  wall,  this  though  lessened  is  not  entirely 
overcome  by  the  most  careful  tamping  of  the  con- 
crete into  the  molds,  since  exact  density  is  impossi- 
ble, but  it  is  found  that  walls  gradually  become  less 
penetrable  to  water  or  moisture.  This  would  be 
true  if  the  blocks  were  made  of  stone,  f or  ^ these  as  a 
rule  would  be  even  more  porous  still.  This  penetra- 
tion of  moisture  is  mostly  objected  to  where  decora- 
tions, plaster,  paper,  etc.,  are  applied  direct  to  the 
inside  face  of  the  wall.  .Many  kinds  of  washes  of 
solutions,  chemicals,  etc..  have  been  used,  but  usually 
with  little  result.  (In  the  next  Chapter  we  will  give 
the  "Sylvester  Process,"  the  only  one  of  any  recog- 
nized value.)  To  avoid  this  moisture  penetration 
there  are  two  forms  of  blocks  on  the  market  which 
easily  excel  all  others.  The  first  block  is  a  two- 
70 


piece  block — front  and  back — and  is  made  with  long, 
middle  web  and  short  end  webs.  The  through  up- 
ri^it  joint  is  broken  by  a  half  length,  when  the  up- 
right joints  occur  alternately  on  face  and  back  with 
the  web  also  bonding  alternately  from  one  side  and 
then  the  other,  thus  while  forming  one  of  the  most 
scientific  bondings  known  to  the  building  engineer, 
it  also  possesses  the  advantage  of  disconnected  lat- 
eral web,  and  in  this  way  avoiding  "Capillary  At- 
traction" of  moisture. 

The  second  is  an  L-shaped  two-piece  block  a 
most  simple,  yet  sensible  design,  admitting  of  the 
greatest  variation,  damp  proof,  with  ideal  bond. 

To  the  manufacturer  of  building  blocks  who 
wishes  to  maintain  a  reputation  against  competitors 
and  a  credulous  public,  three  things  are  of  utmost 
importance.  First  by  tests  a  safe  proposition  ^  of 
concrete  must  be  established,  when  it  must  be  strict- 
ly adhered  to,  the  celnent  used  should  be  tested  or 
warranted  by  the  company  and  must  be  a  high 
grade,  slow  setting  Portland  cement;  the  sand  should 
be  screened  and  uniform.  Second,  in  mixing  the 
concrete  for  the  blocks,  onlv  'enough  must  be  mixed 
at  a  time  so  that  it  can  easily  be  worked  up  before 
the  initial  setting  occurs.  In  mixing,  the  whole  must 
be  thoroughly  and  evenly  incorporated  while  dry.  It 
is  then  slowly  sprinkled  while  it  is  being  worked 
over  until  the  whole  mass  is  as  moist  as  fresh  earth, 
or  wet  enough  so  the  water  will  show  on  surface  if 
well  tamped,  but  must  not  quake  in  tamping.  Every 
batch  must  be  mixed  like  it  in  every  way,  if  the 
thorough  and  even  mixing  is  not  strictly  observed, 
damaging  results  will  follow.  Third,  when  the  molds 
are  hand  tamped  the  greatest  care  is  necessary  in 
the  thorough  and  even  tamping,  also  that  the  form  is 
always  properly  closed  in  latch  to  secure  uniformity 
of  size,  also  that  the  face  of  mold  is  kept  clean, 
making  a  clear  cut  impression  each  time.  It  should 
be  remembered  that  a  responsible  manufacturer  of 
blocks  could  be  held  for  damages  resulting  from  un- 
reliable work.  The  writer  has  known  where  one 
block  placed  in  an  important  building  has  shown 
careless  or  incompetent  work,  resulting  in  litigations 

71  * 


iand  mistrust,  entirely  stopping  a  well  equipped  plant. 

No  careless  or  slipshod  person  should  ever  be  em- 
ployed in  such  exacting  work. 

It  would  be  impossible  to  give  fast  formulas  for 
blocks.  This  should  be  ascertained  as  shown  under 
concretes  or  by  actual  briquet  tests,  but  the  formu- 
las given  will  be  found  nearly  right. 

For  facing  for  blocks,  %  to  1  inch:  Cement,!; 
screened  sand,  2  parts. 

For  body  of  blocks:  Cement,  1;  coarse  sand,  3; 
aggregate,  4. 

Where    no    facing   is    used    the    expense    of   the 
block  will  be  more  than  in  the  above,  since  only  sand 
can  be  used  with  the  cement,  thus  requiring  more 
-  surface  coating,  etc. 

For  complete  block  (face  and  body):  Cement,  1 
part;  sand,  3  parts. 

The  blocks  should  remain  on  the  pallets  for  36 
hours,  and  after  24  hours  shduld  be  kept  wet  and 
covered  from  the  sun  and  currents  of  air.  In  6  or  8 
days  they  are  seasoned  and  in  14  days  can  be  laid 
in  wall.  In  cool  weather  the  drying  is  retarded; 
they  will  require  less  water  but  more  time  to  be 
ready  for  the  wall. 

In  the  last  part  of  the  book  we  will  give  direc- 
tions for  coloring  of  face  work,  which  see. 
Fence   Posts. 

We  have  already  spoken  of  posts  in  this  Part,  but 
under  the  head  of  stationary  castings.  This  con- 
cluded with  the  posts  built  directly  on  the  spot  where 
used.  Under  this  head  we  will  speak  of  the  post  as 
a  commercial  or  portable  product,  which  would  in- 
clude the  smaller  posts,  such  as  fencing  posts.  In 
this  line  great  demand  is  felt  at  the  present  time. 
Reliable  post  timber  is  rapidly  disappearing  from 
our  country.  In  large  sections  this  is  already  upon 
us.  Iron  in  some  cases  has  been  tried,  but  on  ac- 
count of  corrosion  their  life  is  comparatively  short. 
Too,  their  body  is  so  small  that  in  soft  and  yielding 
ground  and  in  thawing  weather  they  are  kept  erect 
only  with  constant  care.  The  uses  of  posts  are  va- 
ried, and  in  this  little  space  we  can  only  give  gen- 
eral instructions,  but  these  can  be  adjusted  by  the 
72 


worker  to  suit  the  many  needs  such  as  posts  for  wire 
fence,  for  board  fence,  to  hang  gates,  on,  etc.  For 
these  posts  as  a  commercial  product,  to  handle,  etc., 
it  will  be  necessary  to  reduce  the  bulk  to  the  mini- 
mum while  retaining  the  strength,  and  at  the  same 
time  secure  slight  elasticity  by  reinforcing  by  metal. 
This  method  is  not  so  new  as  by  some  supposed.  It 
has  been  well  tested  in  this  country,  where  in  some 
sections  they  are  extensively  used  and  with  assured 
success.  In  Belgium,  France  and  Germany  they 
have  been  tested  by  many  years  of  use. 

We  will  consider  a  post  for  farm  fence  use.  This 
post  should  be  6^/2  feet  long,  5  inches  square  at  the 
bottom  and  3  inches  at  the  top  end.  Make  two  side 
form  for  this  post  of  surfaced  boards  5  inches  wide 
at  bottom  and  3  at  top.  To  make  them  stiff  so  they 
will  not  crowd  out  in  tamping  the  concrete  into 
them,  nail  edge  of  strip  IV2  x4  inches,  and  4Mj  feet 
long  against  outside  of  each  form,  driving:  the  nails 
from  inside  of  side  form  through  into  the  stiffening 
strip.  This  while  light  to  handle,  will  remain  true. 
Take  board  5  inches  wide,  into  it  saw  and  cut  out 
grooves  at  right  angles  with  edge  of  board  5  inches 
apart  and  fitting  over  the  bottom  end  of  the  side 
forms;  take  a  board  3  inches  wide  and  do  the  same 
for  top  end  so  that  when  the  form  is  together  the 
space  on  the  inside  will  measure  3  x  3  at  top  and 
5  x  5  at  bottom  end.  The  ends  can  be  held  in  place 
by  wood  screws.  Lay  the  form  on  a  pallet  (sur- 
face board  1"  wide  and  T  long),  on  which  it  can  re- 
main until  seasoned.  The  board  must  be  laid  on 
floor  or  even  ground,  so  that  the  concrete  can  be 
tamped  without  springing  the  board.  When  all  is 
ready  mix  the  concrete,  cement,  1;  sand,  2%;  finish 
aggregate,  3  or  4  parts.  See  Mixing  under  "Con- 
crete." When  the  concrete  is  ready  place  some 
into  the  form,  only  enough  so  that  when  tamped  it 
will  be  about  1  inch  thick  in  bottom  of  form;  upon 
this  place  2  crimped  wires,  No.  9,  and  about  6  feet 
long;  place  the  wires  along  each  side  about  1  inch 
in  from  the  out  edge  and  in  line  with  the  edge. 
This  will  leave  them  about  1  inch  apart  at  the  top 
and  3  at  the  bottom;  upon  this  place  concrete  and 
73 


tamp  until  full  within  one  inch  of  top;  place  in  two 
more  wires  as  before  and  fill  to  the  top;  tamp  solid 
and  stroke  even  with  trowel.  While  it  is  desired 
to  have  the  wires  near  the  outer  surface,  yet  they 
must  in  all  cases  be  well  covered  at  sides  and  ends 
or  they  will  corrode.  Crimped  wire  can  be  bought 
by  the  roll  in  any  size  to  suit.  If  wire  heavier  than 
3/16  inch  thick  is  used  they  are  apt  to  spring  in 
tamping  and  in  this  way  remain  loose  at  some  points 
in  their  length.  It  is  the  experience  of  the  writer 
that  where  4  wires  are  used,  No.  9  is  amply  strong. 
Where  it  is  desired  to  use  only  one  bonding  in  the 
post  as  is  often  done,  a  V2  x  %  inch  iron  rod  is  used; 
this  should  be  twisted.  Twisted  wrought  iron  is  car- 
ried in  stock  in  the  cities  for  the  purpose  of  rein- 
forcing concrete.  When  the  post  as  described  is 
molded,  it  is  left  where  it  is,  on  the  pallet;  the  form 
is  removed  by  first  removing  the  wood  screws,  an- 
other is  built  in  like  manner  and  this  can  be  con- 
tinued at  will.  It  should  be  remembered  that  green 
posts  should  not  be  carried  on  the  pallets  by  taking 
hold  of  the  ends  as  the  springing  of  the  board  might 
break  the  bonding  in  the  middle,  thus  causing  de- 
fects. About  the  way  of  fastening  the  fencing  to  the 
post.  Where  it  is  desired  to  spike  or  nail  to  a  post, 
a  nail  block  or  strip  is  bolted  to  the  top  and  for  this 
purpose,  in  making  the  post  set  an  iron  pin  %  inch 
thick  into  a  hole  bored  into  the  pallet  at  the  proper 
place,  say  6  inches  from  top  of  the  post  and  ex- 
actly in  the  middle;  3  feet  from  the  top  set  another 
pin  in  the  pallet  in  the  same  way;  mold  the  post 
around  these  pins.  When  through  and  before  re- 
moving form,  slightly  tap  the  bolts  with  hand  to 
loosen,  then  pull  them  from  the  post.  Through  these 
holes  %  inch  bolts  will  pass  into  the  nail  strip,  hold- 
ing it  into  place.  This  post  can  be  set  to  nail  into  the 
broad  side  of  the  2x4,  or  set  so  that  the  nailing  is 
attached  to  the  edge,  which  we  think  the  better  way. 
When  it  is  desired  to  attach  wire  to  the  posts, 
bore  holes  at  the  proper  places  into  the  pallets  to 
correspond  to  the  spaces  of  the  wire,  and  so  as  to  be 
in  the  middle  of  the  post;  into  these  set  1A  inch  pins; 
build  around  them;  remove  them  when  done. 
74 


Through  these  the  wire  can  be  stretched,  or  as  some 
prefer,  make  grooves  across  the  face  %  inch  deep 
at  the  proper  spaces  for  the  wires;  secure  the  wires 
into  these  grooves  by  passing  a  wire  around  the  back 
of  the  post,  holding  them  into  position.  There  is 
still  another  way  used  by  some. 

Take  a  No.  12  wire  and  with  wire  pincers  bend 
loops  into  the  ^vire  extending  out  f  ror^  the  line  of 
the  wire  l1/^  inches;  these  loops  must  be  at  the 
proper  places  or  spaces  for  the  wire.  When  the  form 
is  filled  within  1  inch  of  the  top,  place  this  wire 
along  the  middle  of  the  front  face,  with  loops  ex- 
tending past  the  surface  of  the  face  Vz  inch;  build 
this  in  with  the  last  inch  of  the  concrete. 

There  are  many  other  devices  of  fastenings,  but 
these  are  mostly  patented.  A  good  fastening  is  a 
copper  wire  laid  across  face  of  post  at  proper  space 
1  inch  deep  and  projecting  from  either  side  3  inches. 
These  ends  are  twisted  about  fence  wire  and  will 
hold  it  in  place.  Should  one  end  break  with  many 
changes  of  twisting  and  untwisting,  the  other  is 
still  left  for  use. 

The  cost  would  be  the  important  thing  in  this 
work.  While  good  it  might  be  so  expensive  as  to 
be  prohibitive.  Let  us  compute  the  cost.  At  this 

Eoint,  as  perhaps  almost  anywhere,  one  sack  of  Port- 
md  cement  could  be  bought  by  taking  a  small  quan- 
tity for  40  cents;  when  measured  it  will  be  seen  to 
contain  about  1,900  cubic  inches — the  space  occupied 
by  the  post  described  would  be  1,248  cubic  inches. 

Now  in  the  formula  given  for  post  concrete, 
cement,  1 ;  sand,  2 1/2 ;  aggregate,  3  to  4,  we  would 
have  approximately  7  volumes,  and  according  to 
usual  shrinkage  in  filling  voids,  and  tamping,  the  7 
volumes  would  fill  only  4^  volumes  when  tamped 
into  molds.  Since  a  volume  represents  1,900  cubic 
inches,  .4  ^  volumes  equal  1,900  X  41/4  =8,075  cubic 
Inches.  Since  one  post  occupies  1,248  cubic  inches, 
one  sack  of  cement  would  build  8,075^1,248  posts. 
Then  it  will  be  seen  that  one  post  costs  in  cement  at 

45c  per  sack   7c 

and  %  bushel  sand  and  gravel 3c 

Reinforcing  metal , . .  2c 

75  C 


Labor  (one  man«  making  40  posts  per  day) 4<S 

Total  cost  of  post  (without  forms) 16c 

Thus  it  will  be  seen  that  for  16  cents  a  cement 
post  could  be  built  in  an  average  locality.  This 
would  not  be  the  price  of  a  good  timber  post,  the  life 
of  which  would  not  be  over  10  or  15  years,  while  the 
cement  post  would  be  practically  indestructible. 
These  posts  must  be  seasoned — kept  wet  and  shaded 
from  hot  sun  and  currents  of  air  for  6  days.  In  4 
weeks  they  are  ready  for  use.  There  are  machine 
molds  for  fence  posts  These  are  secured  by  pat- 
ents, but  where  many  posts  are  required,  this  method 
would  be  the  cheapest  in  the  end,  because  of  the  rapid 
and  more  systematic  way  of  building. 

Troughs. 

For  stock  watering  and  storage  purposes.  In 
shape  these  are  most  usually  built  rectangular.  A 
usual  size  for  watering  purposes  is  8  feet  long,  2 
feet  wide  at  top  and  18  inches  at  bottom,  and  18 
inches  high  inside.  They  can  be  built  directly  on  a 
porous  foundation  or  o,n  a  bench  block  of  concrete 
set  in  from  each  end  2  feet.  These  could  be  2% 
feet  long,  1  foot  wide,  and  the  height  desired.  Block 
out  the  bottom  between  these  benches,  and  to  the 
end  of  the  trough;  over  the  concrete  of  the  benches 
place  heavy  paper,  so  that  the  trough  will  form 
no  contact,  when  it  can  be  moved  if  desired.  Where 
no  reinforcing  is  used  the  bottom  should  be  5  inches 
thick  and  the  sides  and  ends  4.  With  these  dimen- 
sions in  mind  build  the  outside  form,  with  rough 
boards,  also  an  inside  form  in  the  same  way.  Set 
the  outside  form  on  the  bottom  already  prepared;  fill 
with  concrete  5  inches  deep;  now  set  inside  form, 
with  equal  spaces  between  sides  and  ends;  secure  so 
there  can  be  no  bulging  in  tamping;  fill  in  the  con- 
crete and  tamp.  When  even  with  form,  smooth  top 
and  dub  edges  with  trowel  or  edger.  After  it  is 
set  the  outside  form  is  removed,  and  the  inside 
should  be  removed  as  soon  as  done  or  set,  or  the  ex- 
pansion will  break  the  corners.  Where  it  is  de- 
sired to  have  drain  hole  near  bottom,  this  can  be 
accomplished  in  the  following  way:  For  a  wooden 
76 


plug  opening,  place  a  well  rounded  plug — well  ex- 
panded in  water  before  used — into  the  place  where 
the  outflow  is  desired;  build  around  this  with  a  few 
trowels  of  mortar,  or  if  an  iron  faucet  is  desired 
use  a  common  faucet,  with  a  flange  of  sheet  metal 
soldered  to  it  and  projecting  a  few  inches  from  the 
faucet.  This  flange  is  built  into  the  wall  of  concrete, 
and  secures  against  leakage. 

At  the  end  of  24  hours  the  trough  is  sprinkled  and 
against  the  wet  surface  is  plastered  inside  and  outside. 

Concrete  for  this  work  should  be  as  follows: 
Cement,  1;  sand,  3;  aggregate,  fine,  3  parts. 

Mortar  for  the  surface  coating:  Cement,  1;  fine 
sand,  2  parts. 

Another  method  to  build  these  troughs  is  similar 
to  the  one  described,  only  that  the  inside  form  is  not 
used.  The  concrete  is  used  a  little  wetter  and  is 
built  up  with  trowel  against  the  outside  form,  the 
inside  face  being  guaged  with  trowel.  After  a  few 
hours  the  inside  is  plastered,  etc. 

A  better  and  lighter  trough  is  built  with  the  use 
of  expanded  metal — light  sheets.  These  are  placed 
midway  between  the  surfaces  of  the  wall  when  the 
wall  need  only  be  heavy  enough  to  cover  the  metal,  say 
3  inches,  and  the  bottom  in  the  same  way  4  inches. 

Circular  troughs  are  now  being  built  without 
form,  in  the  following  way:  Build  circular  bottom  on 
such  foundation  as  desired.  When  the  concrete  on 
bottom  is  2  inches  thick,  place  expanded  metal  sheets 
over  this  surface  and  on  top  of  this  place  2  more 
inches  of  concrete.  For  the  side  have  two  metal 
hoops  made,  for  bottom  and  top,  1  x  %  inch;  see  that 
they  are  circular,  and  to  them  fasten  with  light  wire 
a  sheet  of  expanded  lath  metal,  18  or  24  inches  wide. 
The  top  hoop  should  be  fastened  about  4  inches 
down  from  the  top  of  metal,  and  the  bottom  should 
extend  down  and  meet  the  metal  in  the  bottom;  now 
with  the  hands  or  tongs  bend  the  top  of  the  metal 
out  evenly.  This  will  give  the  top  a  more  pleasing 
appearance.  When  the  lathing  and  hoops  are  set 
true  and  secure,  plaster  with  heavy  mortar  the  put 
and  insides  alternately  until  about  2%  inches  thick. 
Care  must  be  taken  that  the  metal  is  not  sprung  in 
77 


the  last  applications.  This  can  be  avoided  by  apply- 
ing the  last  coats  more  plastic. 

This  same  method  could  also  be  applied  to  rect- 
angular tanks,  but  a  circular  tank,  all  other  things 
being  equal,  is  the  strongest.  Where  the  metal  side 
sheet  meets,  it  should  be  lapped  6  or  8  inches. 

Also  in  the  plastering,  the  surface  should  not  be- 
come dry  before  the  additional  coat  is  applied,  or 
adhesion  will  be  imperfect,  scaling  off.  Season  prop- 
erly, and  after  36  hours  fill  with  water  if  convenient. 

Tanks 

Usually  for  storage  purposes,  are  built  much  like 
troughs,  which  see.  However,  they  are  mostly 
deeper,  and  consequently  must  withstand  greater 
inside  surface  pressure.  For  this  purpose,  tanks  are 
reinforced  by  metal,  expanded  metal,  metal  lathing, 
or  wire  netting,  systematically  encased  in  the  shell 
of  the  wall.  See  Troughs.  The  shapes  of  tanks  vary 
with  their  use,  but  are  usually  round,  and  where 
large  should  be  built  where  used.  The  metal  of  the 
bottom  and  sides  should  be  carried  into  each  other, 
so  that  there  will  be  no  separation  at  the  joining  of 
the  bottom  and  side  walls. 

These  circular  forms  are  usually  built  in  sections 
in  such  a  way  as  to  be  most  easily  placed,  and  again 
most  easily  removed  when  through  without  jar  to 
the  casting.  The  forms  are  laid  by  for  similar  work. 
In  this  way  the  cost  of  the  form  to  the  regular  work- 
man is  greatly  reduced.  The  inside  face  must  al- 
ways be  well  plastered,  as  soon  as  the  body  of  the 
concrete  is  hard  enough  to  allow  trowel  work. 

The  concrete  and  mortar  used  in  the  construction 
of  tanks,  as  well  as  the  plan  of  work  is  the  same  as 
for  troughs,  which  see  in  connection  with  this 

article  on  tanks. 

Chimney  Tops 

Can  be  built  with  concrete  much  cheaper  than  with 
stone.  The  form  for  these  can  be  constructed 
quickly  and  is  inexpensive.  When  the  size,  number 
of  flue  holes,  and  their  position  are  known. 

A  small,  even  floor  space  is  selected  or^  made, 
upon  which  the  form  is  built  or  set.     The  thickness 
will  depend  on  the  size,  and  the  number  of  flue  holes 
78 


it  is  to  cover,  but  will  usually  be  from  3  to  six  inches. 
Tack  together  strips  for  outside  edge;  one  corner 
should  be  held  by  a  wood  screw  which  when  removed 
will  allow  the  form  to  spread  when  it  is  removed, 
without  any  jar.  This  outside  edge  when  desired  could 
be  made  with  molding,  thus  giving  a  better  effect. 

The  flue  holes  r  -  o  next  blocked  out.  When  the 
form  is  tamped  hail  full  of  cement  wire  is  spread 
over  this  in  such  a  way  as  to  bind  most  completely 
all  parts;  over  this  fill  the  form  with  concrete  and 
finish.  The  tops  are  sometimes  built  direct  in  place. 
To  support  the  frame  on  the  chimney  place  two  small 
rods  across  the  chimney,  on  these  set  the  form;  when 
completed  these  are  removed  and  the  holes  closed 
with  trowel.  Always  wet  the  top  of  brick  on  chimney 
before  laying  on  or  building  top,  so  as  to  form  con- 
tact with  surface. 

The  composition  of  the  concrete  for  this  work 
should  be,  cement,  1;  sand,  3;  aggregate,  4  parts. 

Well  Beds 

For  the  ordinary  use  of  covering  wells  or  cisterns 
and  supporting  pump,  etc.,  may  be  built  from  con- 
crete in  the  following  manner:  These  are  usually 
from  3  to  6  feot  square  and  if  reinforced  with  ex- 
panded metal  or  heavy  wire  netting  should  be  from 
3  to  4  inches  thick.  When  built  without  reinforcing 
they  should  be  from  4  to  6  inches  thick.  Use  scant- 
ling of  proper  height  desired  for  the  outside  form. 
At  three  corners  these  can  be  nailed  or  spiked,  but 
at  the  fourth  corner  should  be  secured  in  such  a 
way  as  to  admit  of  its  easy  loosening  when  it  is 
spread  and  removed  from  the  cast.  This  form  can 
be  laid  on  an  even  surface  of  ground  lightly  covered 
with  sand;  the  holes  for  pump  or  pipes  are  blocked 
put;  this  now  is  filled  with  concrete  well  tamped 
in  place  to  within  %  inch  of  the  top;  this  is  filled 
with  mortar  as  in  sidewalks. 

If  reinforcing  is  used  place  the  metal  as  near  the 
bottom  of  the  slab  as  convenient,  and  at  the  same 
time  covering  from  the  air.  When  carried  to  the  top 
with  concrete  and  mortar  and  top  surfaced  ^smooth 
with  float,  dub  the  outside  edges  with  a  sidewalk 
edger.  The  concrete  and  mortar  top  should  have  the 
ft  79 


same  composition  as  for  sidewalks  (which  see). 
Sewers. 

In  many  places  these  are  built  of  concrete,  round 
or  spherical  shape,  to  meet  special  requirements  in 
city  construction. 

The  molds  are  made  of  metal,  set  on  smooth  sur- 
face, with  the  flange  up.  Heavy  sewers  or  those 
having  thick  shell  are  tamped  with  finish  concrete, 
while  the  lighter  ones  are  poured  with  liquid  con- 
crete. The  shells  vary  with  the  use  for  which  they 
are  designed,  and  size;  perhaps  from  2  to  4  inches 
would  cover  the  most  common  uses. 

Expanded  metal  sheets  or  wire  netting  are 
usually  used  in  their  construction.  The  proper  width 
of  sheet  is  secured;  they  are  then  cut  into  suitable 
lengths,  lapped  like  hoop?  and  secured  with  light 
wire  ties.  They  are  then  set  into  the  mold;  when 
cast  will  be  entirely  encased  in  the  shell  of  the  sewer. 
The  composition  for  these  sewers  is,  cement,  1^ 
coarse  sand,  3  to  4  parts. 

They  are  usually  built  by  machine  molds,  but  in 
a  small  way  could  be  built  from  hand  molds  very 
simply  constructedp  but  wyald  require  some  skill  in 
the  management  to  insure  satisfactory  product. 
Statuary  and.  Ornaments. 

On  this  subject  we  feel  it  useless  to  say  much  in 
this  little  work.  Yet  cement  has  entered  this  field 
of  work  so  extensively  that  a  few  suggestions  to  the 
amateur  may  not  be  out  of  place. 

The  building  or  casting  of  forms  for  this  line  of 
work  belongs  to  the  specialist. 

For  ornamental  work,  only  very  fine  sand  can  be 
used,  which,  ap  well  as  the  cement,  is  run  through 
a  fine  sieve0  rejecting  any  coarse  or  lumpy  particles 
in  either  sand  or  ement. 

The  proportion  of  cement  and  sand  now  mostly 
used  are  1  to  1.  Formerly  cement  only  was  used, 
but  much  better  results  have  been  obtained  where 
sand  as  indicated  has  been  used.  The  surface  of 
neat  cement  casts  usually  showing  hair  cracks  in 
time.  One  object  in  ornamental  work  is  to  show 
clean  and  distinct  outline  in  the  cast.  The  molds 
are  usually  poured  out  with  liquid  mortar — in  some 


cases  plastic  mortar  is  also  used. 

If  it  is  desired  to  color  statuary  or  relief  work, 
see  Coloring,  under  Part  V.  I  have  seen  many  pieces 
of  cement  statuary  so  artistically  executed,  colored, 
filled  and  polished  as  to  please  the  most  critical 
observer.  -I  have  also  seen  a  few  pieces  in  this  line, 
in  which  the  molds  as  well  as  the  cast  figure  were 
the  product  of  an  amateur  and  showed  considerable 
skill,  and  I  wondered  whether  indeed  this  cheap- 
ened method  might  not  mount  on  pedestals  many 
artistic  urns,  busts  or  other  simple  statuary  in  many 
rural  homes. 

Poverty  does  not  take  true  poetry  from  the  soul, 
but  rather  intensifies  it,  and  but  for  the  cost  a  Her- 
cules would  support  upon  his  muscular  shoulder  the 
columns  of  many  an  humble  home.  Beautiful  vases 
could  be  built  on  pedestals  on  the  lawn,  or  from 
copings  of  porch  or  step  walls.  Niches  in  halls  could 
contain  busts  of  ideal  characters. 

PART    V. 

PRACTICAL  NOTES  ON  CEMENT  WORK. 
Hair  Cracks 

Appear  as  fine  lines  like  a  hair  net  covering  the 
wlole  surface  of  some  troweled  cement  work.  They 
onJy  begin  to  appear  in  the  last  stages  of  the  hard- 
ening, and  mostly  on  work  which  has  been  seasoned 
in  v,he  open  air.  The  causes  of  hair  cracks  may  be 
either  one  or  all  of  the  following:  Overrich,  ovcr- 
wet,  or  overtroweled. 

lo  prevent  hair  cracks  in  rich  mortar,  great  care 
must  be  taken  to  finish  top  surface  with  as  little 
troweling  as  possible,  especially  when  using  metal 
trowd  or  float.  The  stroking  crowds  the  heavier 
partides  of  sand  downward  into  the  mass,  this  h> 
turn  forces  the  finer  particles  of  cement  with  the 
water  ;o  the  top  surface  covering  the  surface  with  a 
neat  cement  liquid  which  in  drying  forms  a  glossy 
cover  called  "skin  cover."  This  in  the  later  stages 
or  hardening  contracts,  as  all  neat  cement  liquids 
will,  leaving  so-called  "hair  cracks."  This  is  very 
fauliy  and  will  be  rejected  by  the  engineer  or  in- 
81 


spector.  Mortar  should  first  be  spread  with  trowel, 
but  the  trowel  should  not  be  held  in  such  a  way  as 
to  cover  air  spaces,  or  suck  them  ihto  the  mass.  Do 
not  try  to  even  the  surface  with  trowel,  but  at  this 
point  take  wooden  float  or  straight  edge  and  stroke 
the  top  off  even.  Now  let  lay  until  the  water  is 
mostly  evaporated,  but  before  set  finish  the  top  as 
desired.  When  mortar  contains  50  per  cent  or  more 
of  sand,  as  all  well  regulated  mortars  should,  and 
only  enough  water  for  plasticity,  and  with  these 
directions  on  troweling  observed,  no  hair  crack  will 
ever  appear. 

Settling  and  Shrinkage  Cracks 
in  walls,  walks  or  floors,  may  be  caused  by  uneven 
settling,  by  heaving  in  frost,  by  jars  in  the  early 
stages  of  setting,  by  shrinkage;  in  walks,  by  joints 
not  being  cut  continuous,  by  irregular  thickness  and 
outline,  causing  weak  points,  or  by  too  large  blocks 
Entire  freedom  from  shrinkage  and  expansion  while 
reduced  to  a  minimum  in  cement,  is  an  ideal  unknown 
to  the  building  trade.  For  this  reason  walls,  floors 
and  walks  must  be  divided  into  sections  which  will 
allow  of  slight  settlings  or  variation  without  rupture 

Long  stretches  of  concrete  in  contracting  will  pull 
asunder  at  the  point  of  least  resistance  or  in  expan- 
sion will  buckle.  Outlines,  either  in  thickness  or 
width,  that  disturb  proportionate  strength  must  be 
avoided.  Some  walks,  either  through  carelessness 
or  for  deception,  are  heavier  at  the  outer  edges  t\an 
through  the  center,  while  the  reverse  should  be  the 
practice.  This  invariably  checks  along  these  veak 
places;  also  a  tree  or  telephone  pole  may  hinder  and 
is  worked  around.  In  this  case  unless  enough  ieay- 
ier  in  depth  to  counteract  width  defects,  thi?  will 
check  across.  The  thoughtful  workman  will  avoid 
this  by  placing  an  open  joint  at  this  point.  Care 
is  also  required  in  floors  and  walks  that  the  top  mor- 
tar layer  is  blocked  off  exactly  with  the  lower  con- 
crete block  or  checks  will  result. 

Irregular  filling  of  the  foundation  will  show  in 

cracks;   also  freezing  which  heaves,  caused  by  too 

shallow  foundations  or  water  in  the  foundatiors  is 

sure  to  break  the  work,  whether  floor,  walk  or  vail. 

82 


Tight  joints  in  blocked  work  are  but  little  better 
than  none.  These  defects  show  in  the  first  year  or 
two  of  the  work. 

Pock    Marks. 

These  are  blotches  or  pippings  in  the  smooth 
surface  of  mortar,  and  will  show  in  the  first  few 
hours  of  the  work.  They  are  caused  by  the  incorpo- 
ration of  air  or  water  or  foreign  matter  in  the  mass, 
which  in  the  process  of  setting  are  forced  to  the  sur- 
face. To  avoid  these  causes  would  in  itself  be  the 
remedy. 

Freezing    Weather. 

When  once  hard  no  hydraulic  material  is  less 
affected  by  extreme  cold  than  Portland  cement  mor- 
tar or  concrete,  but  in  the  early  process  of  set  and 
hardening  it  should  be  protected  from  freezing, 
though  some  cases  are  cited  where  solid  freezing  in 
this  stage  showed  no  damaging  results.  Most  ex- 
perts in  this  line  agree,  however,  that  freezing 
should  be  avoided,  especially  in  surface  work;  zero 
weather  must,  if  possible,  be  avoided.  By  adding  1 
gallon  of  salt  to  20  gallons  of  water  used  in  working 
the  mortar  or  concrete,  and  using  only  a  minimum 
of  this,  would  prevent  freezing  in  ordinary  cold 
weather,  and  outside  of  slight  discoloring  would 
have  no  bad  effect  on  the  quality  of  the  work.  Yet 
some  good  authorities  on  this  subiect  think  that  it  is 
better  to  warm  all  the  ingredients  used,  so  as  to* 
hasten  setting,  and  when  placed  protect  from  freez- 
ing by  covering  with  wet  paper,  then  saw  dust  or 
shavings  or  even  manure,  tarpaulin  placed  over  this, 
leaving  the  whole  until  sufficiently  hard,  which  at 
this  temperature  might  be  from  2  to  6  weeks.  The 
effect  of  freezing  is  shown  by  scaling  off,  showing 
watery,  loose  surface.  In  freezing  weather,  where 
cement  mortar  is  used,  no  free  water  should  work 
from  the  mortar  into  the  surface  of  brick,  stone,  or 
aggregate  used  as  the  water  so  escaped  would  freeze 
and  expand  the  mass. 

Hot   Weather. 

Cement  work  made  in  hot  weather  can  be  equal 
to  that  made  at  any  other  time,  but  greater  care  in 
the  seasoning  is   imperative.     It   must  be   covered 
83 


from  the  rays  of  the  sun  and  currents  of  air,  and 
kept  wet  6  or  8  days;  also  greater  care  is  required 
in  plastering  and  bonding  building  materials,  stone, 
brick,  cement  blocks,  etc.,  but  this  may  all  be  over- 
come by  liberal  application  of  water  to  the  surfaces 
on  which  it  is  desired  to  form  contact.  This  restores 
prime  conditions  for  adhesion.  It  should  also  be  re- 
membered that  during  hot  and  windy  weather  the 
initial  set  is  hurried,  and  mortar  or  concrete  should 
be  sooner  placed,  as  they  cannot  be  reworked. 

Dry  Surfaces  and  Adhesion. 
In  mixing  concrete  the  stone  or  gravel  forming 
the  aggregate  should  not  be  incorporated  into  the 
sand  and  cement  until  their  surfaces  are  moistened, 
but  to  have  them  dripping  wet  is  equally  objection- 
able. It  is  only  required  that  their  surface  is  moist 
enough  so  that  the  particles  of  sand  and  cement 
mixed  when  dry  will  adhere  and  cover  all  the  sur- 
faces of  the  aggregate.  This  alone  constitutes  one 
of  the  most  vital  requisites  of  concrete. 

In  walls  of  either  brick  or  stone  it  is  important 
that  the  mortar  used  in  bedding  should  also  form  a 
bonding  (binding  surface  to  surface).  This  adhe- 
sion differs  with  the  kind  of  mortar  and  materials 
used,  but  is  from  9  to  15  pounds  per  square  inch, 
and  every  workman  should  know  that  when  a  stone 
,  or  brick  with  dry,  hot  and  sometimes  dusty  surface 
'is  laid  into  mortar  very  little  if  any  adhesion  is 
formed,  consequently  in  brick  the  hose  should  be 
turned  on  them  in  the  pile,  that  while  they  are  not 
dripping  wet  they  may  be  moist  through,  and  in 
shape  to  be  laid  to  some  purpose.  Stone  which  can- 
not be  so  easily  immersed  should  in  all  cases  have 
beds  and  joints  sprinkled  before  laid  in  mortar;  in 
fact  in  work  ably  superintended  the  old  dry  sur- 
face, slip-shod  way  will  not  be  tolerated.  The  writer 
has  seen  heavy  walls  constructed  of  large  stone  con- 
taining from  16  to  24  cubic  feet  each,  removed  with 
large  derrick  in  which  it  was  necessary  after  taking 
the  weight  with  derrick  to  jar  the  bed  loose  with  a 
heavy  bar,  and  in  some  cases  carrying  with  it  two 
stones  beneath,  when  less  secure,  beds  broke  their 
rbonds.  When  these  fast  bondings  were  broken  asun- 
84 


der  it  was  found  that  the  cohesion  of  the  cement 
mortar  was  not  broken,  nor  was  the  adhesion  at  the 
stone  broken,  but  a  part  of  the  surface  was  *;orn 
from  the  stone.  If  a  brick  with  the  most  unfavor- 
able conditions  is  laid  into  good  cement  mortar,  after 
dry  it  can  easily  be  lifted  from  the  bond  by  the  hand; 
it  is  loose.  But  on  the  other  hand  if  the  conditions 
are  the  most  favorable  it  would  require  in  a  straight 
steady  pull  448  pounds  to  pull  it  from  its  fastenings. 
This  estimate  is  very  conservative;  some  authors 
claim  tests  of  576  pounds. 

All  walls  and  surfaces  to  be  plastered  with  ce- 
ment must  first  be  sprinkled,  and  if  dirty  must  in 
addition  be  thoroughly  cleaned. 
Portland   as  Against   Natural  or  Common   Cement. 

We  have  spoken  on  this  subject  before  but  lest 
some  one  should  not  distinguish  between  them  we 
will  repeat  what  has  been  said  and  in  addition  give 
some  other  facts. 

In  all  formulas  and  directions  given  in  this  book 
reference  is  had  to  Portland  cement,  only  when  the 
Natural  or  Common  is  indicated  can  it  be  used.  I 
use  the  word  Natural  or  Common  since  I  find  that 
in  some  localities  it  is  known  by  the  name  Natural, 
in  others  by  the  name  Common.  At  this  time  estab- 
lished grades  of  Portland  in  this  locality  cost  in  car 
lots  $1.20  per  barrel  and  retail  at  $1.60  per  barrel. 
The  Natural  in  car  lots  50  cents  and  retails  at  80 
cents.  The  Portland  has  380  pounds  net  to  the  bar- 
rel, the  Natural  300  Ibs.  to  the  barrel.  The  pro- 
ducers of  the  Natural  cement  are  admitt  dly  labor- 
ing under  hopeless  discouragements.  With  the  in- 
creased facilities  for  the  manufacture  of  Portland 
cement  the  prices  have  gradually  gone  down  until 
today  the  competition  has  practically  driven  the 
Natural  cements  from  the  market.  As  indicated  in 
this  article  while  the  price  of  the  Natural  is  about 
one-half  that  of  the  Portland,  and  that  the  Port- 
land is  cheaper  for  any  use  than  the  Natural.  Yet 
the  cost  of  production  of  the  one  does  not  differ  so 
much  from  the  other.  In  four  letters  lying  before 
me,  received  from  four  different  cement  manufac- 
turers of  note,  three  admit  the  passing  of  the  more 
85 


ordinary  natural  cements  entirely  from  the  market. 
The  question  would  naturally  occur  to  the  reader,  are 
all  Portland  cements  equally  good?  They  are  not, 
and  differ  just  as  do  other  commercial  products.  In- 
ferior Portland  cement  could  not  long  hold  up  in  a 
competing  market  where  numerous  tests  are  con- 
tinually made  by  engineers  and  others  using  cement 
in  a  large  way;  also  the  different  organizations  of 
architects  and  engineers  in  each  state  pass  on  all 
cements  largely  used  for  construction,  and  in  this 
way  a  rating  is  often  established.  Sometimes  ce- 
ment from  the  same  mill  falls  below  the  require- 
ments, but  all  good  mills  watch  this  closely  and  such 
inferior  products  are  not  placed  on  the  market  for 
good  Portland.  On  large  work  cements  are  tested 
before  used.  The  small  consumer  can  usually  feel 
secure  in  buying  the  standard  Portlands  largely  used 
on  important  construction.  We  might  name  some 
popular  brands  which  we  know  to  be  good,  but  think 
this  unfair,  because  of  the  many  brands  of  which 
we  know  nothing,  but  which  are  equally  good.  For- 
eign Portlands,  at  one  time  largely  used  in  this 
country,  and  while  still  used  by  some,  actual  tests 
have  shown  our  own  Portland  to  be  equal,  though 
selling  in  the  market  at  one-half  the  price  of  the 
foreign  product.  Portland  and  Natural  cement 
should  never  be  mixed  in  use,  for  in  so  doing  the 
strength  of  the  better  is  reduced  to  that  of  the 
weaker;  nor  should  concrete  madp  fi*orn  fhe  Natural 
be  covered  with  mortar  from  Portland,  for  in  nearlv 
all  such  cases  they  separate  at  the  bed  joint,  caused 
by  unequal  contractions  and  expansions.  Sometimes 
face  walls  in  brick  work  are  carried  up  by  Portland 
mortar  and  the  backing  courses  laid  in  Natural  mor- 
tar; this  is  objectionable  for  the  same  reason,  in 
some  cases  lifting  the  bond  courses  entirely  free 
from  the  other  courses,  ruining  the  work. 

Seasoning  Cement   Work. 

This  begins  when  the  work  is  completed  and  ex- 
tends through  the  stage  of  chemical  action,  and  con- 
tinues to  the  point  of  practical  hardness.  Ultimate 
hardness  in  some  cases  is  only  reached  after  8  or  12 
years. 

m 


The  period  of  seasoning  will  vary  with  the  tem- 
perature and  moisture  of  the  weather.  At  a  tem- 
perature of  about  70°  seasoning  would  require  from 
21  to  28  days.  In  dry,  hot  weather  all  work  either 
concrete  or  mortar  should  be  covered  after  24  hours 
old  to  protect  it  from  currents  of  air,  and  from  the 
sun.  This  covering  should  continue  for  from  6  to  10 
days.  In  addition  to  covering  the  work  must  be  kept 
wet  or  moist  from  6  to  8  days,  after  it  is  24  hours 
old.  The  work  ordinari1-  should  not  le  used  for  21 
days;  this  would  depend  on  the  use  made;  if  a  floor 
it  could  be  lightly  used  when  uncovered,  but  if  a 
drive  for  heavy  teaming  it  should  lay  21  to  28  days. 
These  conditions  of  seasoning  are  prescribed  for  a 
temperature  of  about  70°;  as  the  thermometer  goes 
lower  less  water  is  required,  but  this  extends  the 
period  of  seasoning. 

Measuring  Ingredients. 

The  components  of  concrete  or  mortar  must  never 
be  guessed  at  or  measured  in  such  a  slip-shod  way  as 
by  the  "shovelful."  This  method  sometimes  used  is 
very  unreliable.  The  size  of  a  shovelful  would  de- 
pend on  the  dryness  or  moisture  of  the  ingredients 
used;' also  upon  the  pile  or  box  from  which  it  was 
taken.  A  difference  of  25  per  cent  has  been  shown 
when  the  greatest  care  was  taken  to  have  them 
alike.  On  small  jobs  the  parts  could  be  measured 
with  a  pail  or  basket,  but  <  n  larger  work  make  meas- 
ures, using  one  sack  or  a  number  of  sacks  of  cement 
as  the  unit.  Make  measure  boxes  for  sand  and  ag- 
gregate of  the  proper  size;  these  measures  need  no 
bottom  and  should  have  handles  nailed  on  opposite 
sides  by  which  the  box  can  be  lifted,  allowing  the 
contents  to  spread  over  mortar  box  or  mixing  floor. 
A  sack  of  cement  when  poured  into  a  basket  will 
contain  approximately  1,900  cubic  inches;  by  this  the 
measure  boxes  can  be  gauged  to  the  desired  size. 
Reworking  Mortar  and  Concrete. 

The  mixing  of  mortar  should  be  so  gauged  with 
the  time  and  use  that  it  can  always  be  used  up  be- 
fore requiring  reworking.  Reworked  mortar  loses 
some  of  its  first  qualities  and  much  of  its  initial 
hydraulic  activity,  and  competent  authority  on  this 

87 


subject  declares  that  it  should  be  entirely  discarded* 
Concrete  must  not  be  mixed  before  it  can  be  used,  as 
this  can  never  be  reworked  after  set,  but  must  b& 
thrown  away. 

Forms  for  Cast  Masonry. 

For  portable  work  the  forms  are  mostly  of  metal. 
We  shall  speak  of  wooden  forms  used  on  large  and 
changeable  castings.  All  form  lumber  must  be  sur- 
faced, and  the  forms  so  constructed  that  they  will 
not  yield  or  bulge  when  the  concrete  is  tamped  in 
place.  Forms  also  should  be  so  fastened  or  latched 
as  to  allow  their  easy  removal,  without  jarring, 
crowding  or  hammering.  Forms  can  be  removed  in 
some  cases  of  dryish  concrete  as  soon  as  cast,  others 
should  remain  until  set;  and  some  are  even  left  until 
seasoned.  Wooden  forms  should  always  be  ex- 
panded before  used. 

Wood  Forms  Brushed  with  Hot  Paraffin  Wax. 

The  wax  is  forced  into  the  wood  by  ironing  with 
hot  iron,  This  makes  the  forms  impervious  to  wet, 
when  they  are  easily  kept  straight  and  true. 
Filling  Surfaces  of  Cast  Products. 

When  the  proper  care  is  taken  in  molding  and 
removing  forms  cast  products  are  turned  from  the 
molds  finished.  However,  products  are  sometimes 
slightly  damaged  or  show  rough  surfaces  on  the 
face.  These  can  be  retouched,  but  this  requires  some 
skill,  since  the  retouching  should  not  show.  Moisten 
the  point  repaired  and  with  mortar  or  concrete  of 
similar  consistency  apply  and  brush  over;  do  not  use 
metal  trowel.  When  the  surface  has  become  dry, 
new  adhesion  must  be  formed.  This  is  accomplished 
by  wetting  the  surface  and  with  brush  dipped  into 
liquid  mortar  brush  the  surface  to  be  repaired  and 
then  apply  as  before.  Breaks  in  cement  ware  can 
be  mended  in  this  way:  First,  to  make  the  surface 
impermeable  to  water  and  second,  for  appearance. 
Columns,  statuary  relief  work  and  some  massive 
building  blocks,  etc.,  are  finished  in  this  way,  to 
acquire  uniform  faces  in  color  and  impenetrability 
to  moisture.  For  this  purpose  when  the  cast  is  suf- 
ficiently hard  so  as  not  to  rub  loose  the  surface  is 
soaked.  Over  this  with  brush  apply  liquid  mortar 

88  i 


(composed  of  cement,  1,  and  granite  dust  or  ground 
stone,  1);  thoroughly  rub  this  into  the  pores  of  the 
surface  with  wooden  trowel  or  such  other  instrument 
as  will  conform  with  the  surface  if  not  plain;  wipe 
surface  dry  and  in  24  hours  treat  again  in  the  same 
way,  only  that  at  this  stage  rub  with  cork  float. 
This  finishes  the  face;  the  surface  is  dense,  impene- 
trable, shows  a  surface  to  resemble  rubbed  stone. 
At  this  point  the  "Sylvester  water  proofing  liquid" 
is  in  some  cases  applied,  but  mostly  when  the  ware, 
if  building  blocks,  etc.,  are  placed  into  the  wall.  The 
method  of  mixing  and  applying  is  as  follows:  Dis- 
solve V2  Ib.  shaved  Castile  soap  in  1  gallon  of  water; 
also  dissolve  %  Ib.  powdered  alum  in  4  gallons  of 
water;  when  the  surface  is  dry  apply  the  soap-wash 
at  boiling  heat,  with  brush;  do  not  froth  the  soap. 
After  the  soap-wash  is  thoroughly  dry  apply  the 
alum-wash  in  the  same  way,  only  at  a  temperature 
of  about  70°.  The  applications  should  be  made  twice 
when  it  is  wished  to  secure  perfect  impenetrability  to 
water.  This  securely  closes  all  the  pores  on  the  sur- 
face, and  its  use  on  government  buildings  has  shown 
its  permanence  by  many  years  of  satisfactory  use. 

Coloring    Cement    Work. 

Coloring  matters  are  sometimes  used  in  mortar 
for  decorative  purposes.  Mineral  colors  are  the 
safest.  To  make  colored  stone,  take  the  proportion 
of  coloring  and  cement  and  mix  them  thoroughly 
while  dry,  then  add  the  sand,  etc.,  mix  all  together 
until  of  uniform  color,  then  add  water  and  continue 
to  mix  thoroughly  until  it  is  uniform  throughout. 

For   White   Stone- 
White  Portlnnrt  cement .  1  part       Pulverized   marble  1-2  part 
Pulverized    liuie   1-4    part  Light  colored  sand  1  part 

On  account  of  the  inferiority  of  white  Portland 
Cement  the  above  is  seldom  used. 

Red    Stone  Dark    Blue    Stone 

1    sack   cement.  1  sack  cement 

200    Ibs.    sand  200    Ibs.    sand 

5  Ibs.  violet  oxide  iron  (raw)       4  Ibs.  ultra  marine  blue 

Bright    Red    Stone  Gray    Stone 

1   sack   cement  1  sack  cement 

200   Ibs.    sand  200    Ibs.    sand 

7    Ibs.    English    red  1  Ib.  Excelsior  carbon  black 

Brown  Stone  Black   Stone 

89 


200    fibs,    sand  1  snck  cement 

1  sack  cement  2UO    Ibs.    sand 

4  Ibs.   Browu  ochre  8  tbs.  Excelsior  carbon,  black 

The   ultra  marine  blue  is  found  to  add  to  the 
quality  of  mortar  if  not  used  excessively;  most  other 
coloring  matter  should  be  used  sparingly. 
Testing  Cement. 

When  tests  are  made  with  neat  cement  only  they 
show  the  rating  of  the  cement  as  a  commercial  pro- 
duct; when  cement  and  sand  are  used  we  have  a 
mortar  test,  and  when  aggregate  is  added  a  concrete 
test. 

The  last  two  are  the  most  practical  to  the  work- 
man, Cement  mortars  and  concretes  are  tested  to 
establish  the  chief  characteristics  desirable  in  build- 
ing material.  Hardening  properties,  tensile  and 
cornpressive  strength,  permanence  in  air  or  water, 
resistance  to  weather  conditions,  adhesion,  etc.  The 
quality  most  frequently  tested  on  account  of  con- 
venience and  because  other  qualities  can  be  fairly 
well  rated  from  this,  is  tensile  strength  (pulling 
apart).  For  this  purpose  briquets  are  formed,  under 
regulation  sizes  and  conditions.  These  briquets  at 
the  smallest  or  breaking  point  have  a  surface  of  one 
square  inch  in  mortar,  and  in  concrete  briquets  they 
are  larger  but  the  breaking  strain  is  computed  per 
square  inch.  The  average  of  5  briquets  similarly 
constructed  are  taken  as  a  fair  test.  The  compres- 
sive  strength  (crushing  weight)  is  not  so  simply 
tested,  but  is  found  to  be  almost  uniformly  10  times 
the  tensile  strength  for  an  equal  surface. 

For  an  illustration  of  the  requirements  in  these 
tests  I  would  suggest  "The  Standard  Methods  of 
Testing  and  Specifications  of  Cement,"  which  any 
manufacturer  of  cement  will  be  glad  to  send  you 
free  of  cost  and  which  is  published  under  the  direc- 
tion of  the  American  Society  for  Testing  Materials. 

To  test  constancy  in  volume  of  cement,  make  pat 
of  cement  on  glass  2  or  three  inches  in  diameter  and 
%  inch  thick  in  middle.  After  being  covered  with 
damp  cloth  for  24  hours  place  under  water  and 
watch  for  3  or  4  days  to  see  whether  -it  becomes 
contorted  or  cracked.  These  cracks,  if  expansion 
90 


cracks,  are  widest  at  outer  edge  of  pat  and  extend 
toward  the  center.  Shrinkage  cracks  may  extend 
across  center,  but  can  be  distinguished  from  expan- 
sion cracks.  Shrinkage  cracks  might  denote  no 
fault  of  the  cement,  but  expansion  cracks,  curling  or 
twisting  of  the  pat,  indicate  faulty  or  unseasoned 
cement. 

If  the  time  of  setting  of  cement  is  to  be  known, 
make  a  pat  not  too  wet.  place  on  glass,  cover  from 
the  air,  and  as  soon  as  it  will  resist  slight  pressure 
of  the  finger  nail  or  for  more  accuracy,  as  soon  as 
it  resists  the  pressure  of  a  needle  1/24  inch  in  diam- 
eter, with  pressure  of  1  lb,  the  mortar  is  set.  Tests 
are  only  valuable  as  they  are  made  by  experts;  this 
is  more  especially  true  of  tensile  strength.  Expan- 
sion can  also  be  tested  by  filling-  a  lamp  globe  with 
plastic  mortar;  if  in  hardening  it  is  burst,  expansion 
is  indicated;  also  when  hard  if  a  colored  liquid  is 
poured  on  top  and  filters  in  between  glass  and  ce- 
ment it  shows  contraction.  This  test  is  very  exact- 
ing and  would  condemn  most  cements  on  the  market. 
We  have  not  given  details  in  making  and  testing 
briquets  because  for  the  amateur  it  would  be  worth- 
less. But  we  think  the  methods  and  requirements 
given  sufficient  for  the  lay-workman,  since  the  more 
important  tests  required  in  his  work  can  be  most 
clearly  deducted  from  the  directions  here  given. 

We  herewith  give  a  table  of  tests  made  from  an 
average  of  5  briquets  at  each  test:  1  part  standard 
Portland  cement  to  2  parts  sand: 

Age  of  briquet        Tensile  strength  per  square  inch. 

7    days  193  tfts. 

28    days  238  fibs. 

60   days  2d8  lt>s. 

90   days  273  Ibs, 

Cost  of  Cement  Work. 

To  determine  the  cost  of  mortar  or  concrete  and 
give  fa&f  rules  and  estimates  that  would  be  appli- 
cable in  al!  localities,  differing  not  only  in  the  cost 
and  character  of  materials,  but  also  depending  on 
the  variation  in  prices  of  labor,  and  the  methods  of 
construction  in  general,  would  be  impossible.  In  the 
vicinity  of  Cleveland,  0.,  which  is  perhaps  a  fair 
average  locality,  the  cost  of  a  good  quality  of  sand 
or  aggregate,  delivered  convenient  to  the  work, 
91 


would  be  approximately  5c  per  cubic  foot.  .  This 
would  differ  slightly  with  localities  near  or  remote 
from  shipping  points  or  points  of  natural  deposit 
Cement  itself  is  perhaps  most  uniform  in  cost  of 
any  of  the  components,  and  will  not  deviate  much 
either  east  or  west,  north  or  south,  in  price  for  3 
standard  article.  A  good  grade  of  Portland  cement 
can  be  bought  in  the  vicinity  of  Cleveland,  0.,  at 
present,  for  about  $1.20  per  barrel  in  car  lots,  and 
from  the  retailer  in  small  quantities  for  $1.50  per 
barrel.  This  price  it  will  be  known  may  not  hold 
good  for  any  number  of  days.  Yet  as  a  basis  for 
several  tables  on  the  cost  of  mortars  and  concretes, 
we  shall  use  them;  from  them  the  average  workman 
can  adjust  the  table  to  meet  the  conditions  at  hand. 
It  should  also  be  known  that  in  a  well  proportioned 
mortar  the  volume  of  sand  represents  90  per  cent  of 
the  volume  of  mortar;  this  is  true  in  the  same  way 
of  a  well  balanced  concrete;  in  this  the  aggregate 
represents  90  per  cent  of  the  concrete  tamped  into 
place. 

This,  by  repeated  tests,  has  proven  true  because 
if  well  balanced  the  voids  are  filled  and  in  addition 
the  surfaces  coated,  this  latter  adding  10  per  cent  to 
the  volume  of  the  coarser  component — in  mortar, 
sand;  in  ^concrete,  aggregate.  In  the  tables  the 
labor  is  given  by  estimate  and  in  some  cases  would 
vary.  In  measuring  loose  cement  from  a  box  or  bin 
usually  1900  cubic  inches  make  one  sack,  conse- 
quently 1  cubic  foot,  or  1,728  cubic  inches  would 
cost  about  30c. 

This  table  gives  costs  for  5  grades  of  mortar  with 
cost  of  cement  per  cubic  foot  @  30c  and  sand  @  5c 
per  cubic  foot. 

Extra  Rich — 

C  1,  S  1  equals  2  cub.  ft.  and  costs  35c 

The  2  cub.  ft.  will  lay  only  1  1-2  cub.  ft.  and  costs  when 

laid   per  cub.  ft.    (with  3c  for  labor)    26e 

Rich — 

C  1.   S  2.  equals  cub.  ft.  and  costs    40c 

The  3  cub.  ft.  will  lay  only  2  1-4  cub.  ft.  and  costs  when 

laid    (with  3c  for  labor)   per  cub.  ft 21c 

Good— 

C  1,  S  3  equals  4  cub.  ft  and  costs  45c 

The  4  cub.  ft.  will  lay  only  3  cub.  ft.  and  costs  when 
92 


j  laid   (with  3c  for  labor)   per  cub.  ft 18c 

Fair— 

C  1,  S  4  equals  5  cub.  ft.  and  costs  50c 

The  5  cub.  ft.  will  lay  only  3  3-4  cub.  ft.  and  costs  when 

laid  (with  3c  for  labor)  per  cub.  ft 16c  . 

Weak— 

C  1,  S  5  equals  0  cub.  ft.  and  costs  ooo 

The  6  cub.  ft.  will  lay  only  4  1-2  cub.  ft.  and  costs  when 

laid   (with  3c  for  labor)  per  cub.  ft 15c 

Rich— 

C  1,  S  2  equals  3  cub.  ft.  and  costs  40c 

The  3  cub.  ft.  will  lay  only  2  1-4  cub.  ft.  and  costs  when 

laid    (with  3c  for   labor)   per  cub.  ft 21c 

Good — 

C  1,  S  3  equals  4  cub.  ft.  and  costs   4oc 

The  4  cub.  ft.  will  lay  only  3  cub.  ft.  and  will  cost  when 

laid   (with  3c  for  labor)  per  cub.  ft 18c 

Fair— 

C  1.  S  4.  equals  5  cub.  ft.  and  costs  50c 

The  5  cub.  ft.  will  lay  only  3  3-4  cub.  ft.  and  costs  when 

laid   (with  3c  for  labor)  per  cub.  ft ..16c 

Weak— 

C  1,  S  5  equals  6  cub  ft.  and  costs   ooc 

The  6  cub.  ft.  will  lay  only  4  1-2  cub.  ft.  and  costs  when 

laid  (with  3c  for  labor)   per  cub.  ft.   15c 

This  last  mortar  is  slightly  porous,  but  for  cer- 
tain work  is  considered  passable. 

Concrete  for  light  wares,  and  smooth-faced  work 
is  composed  of  coarse  and  fine  sand  mixed  cement, 
costing  30c  per  cubic  foot,  and  sand  5c  per  cubic  foot. 

Rich— (Dense)— - 

C  1,  S  2,  A  8  equals  6  cub.  ft,  cost   5oc 

The  6  cub.  ft.  will  lay  only  3  3-4  cub.  ft.  and  costs  with 

labor  when  laid,  per  cub.  ft 18c 

Rich— (Porous) — 

C  1,  S  2,  A  6  equals  0  cub.  ft.  cost   70c 

The  0  cub.   ft.   will   lay   ouly  6  cub.   ft.   and   costs  with 

labor  when  laid,  per  cub.  ft 15c 

('Hood — (Dense)— 

C  1,  S  3,  A  5  equals  9  cub.  ft.,  cost  70c 

The  9  cub.  ft.  will  lay  only  5  1-2  cub.  ft.  and  costs  with 

labor  when  laid,  per  cub.  it 16c 

Good — (Porous) — 

C  1,  S  3,  A  9  equals  13  cub.  ft.,  cost 90c 

The  13  cub.  ft.  will  lay  only  8  3-4  cub.  ft.  and  costs  with 

labor   when    laid,    per   cub.   ft 13c 

Fair — 

C  1,  S  4,  A  7  equals  12  cub.  ft.,  cost   85c 

The  12  cub.  ft.  will  lay  only  7  1-2  cub.  ft.  and  costs  with 

labor   when    laid,    per   cub.    ft     14c 

Weak— 

C  1,  S  5,  A  9  equals  15  cub.  ft.,  cost   $1.00 

The  15  cub.  ft.  will  lay  only  9  1-2  cub.  ft.  and  costs  with 
labor   when   laid,    per   cub.   ft 13c 

Concrete  made  from  cement?  sand  and  aggregate, 
92 


cement  costing  30c  per  cubic  foot  and  the  sand  and 
aggregate  5c  per  cubic  foot,  with  an  allowance  of  3c 
per  cubic  foot  for  mixing,  laying  and  tamping,  as 
follows : 

Four  Methods  of  House  Construction  in  Cement. 
The  most  popular  method  in  house  construction 
used  in  the  United  States  is  the  hollow  block  method. 
For  this  the  architect  selects  one  or  more  of  the 
many  styles  of  blocks  now  in  the  market.  The  face 
of  wall  may  be  either  rock  face  in  courses  or  rubble 
work.  Smooth  face  representing  rubbled  stone  work. 
Tool  or  ornamental  design,  to  suit  the  taste  of 
builder.  This  usually  is  trimmed  with  belt  courses, 
etc.,  in  suitable  style.  The  color  may  also  be  taken 
advantage  of.  But  in  this,  as  well  as  in  wood  work, 
"over  effect"  must  be  guarded  against.  For  dwell- 
ings, if  the  hollow  blocks  have  continuous  webs,  it 
will  be  best  to  stud  and  lath  inside  walls  for  plaster- 
ing, or  instead  run  brick  or  tile  lining  to  receive 
plastering  and  decorating. 

Another  method,  the  veneer  block,  does  not  differ 
in  outward  appearance  from  the  hollow  block.  For 
veneer  work,  use  frame  as  for  wood  house,  stud  and 
sheet,  but  leave  room  on  outer  edge  of  wall  for 
veneering,  usually  4  or  5  inches.  The  veneering  is 
carried  up  from  this  point  to  the  height  desired,  in 
some  cases  bound  to  frame  work  by  spikes  driven  into 
frame  work  and  projecting  into  bed  joints  of  wall. 

A  third  method,  largely  used  in  Europe  and  com- 
ing into  use  in  this  country,  is  the  monolithic  method. 
This  consists  of  a  wall  of  cement  concrete  built  up  in 
one  continuous  piece,  hollow  or  solid,  as  desired.  The 
molds  for  this  work  are  carried  up  as  the  wall  pro- 
gresses and  are  reinforced  by  the  use  of  lateral  rods, 
wires,  expanded  metal,  or  wire  netting,  as  thought 
most  practical  for  the  requirements  of  walls.  Sec- 
tions weakened  by  perpendicular  openings  for  win- 
dows or  doors  require  extra  reinforcing  along  these 
weakened  lateral  sections,  or  in  the  contraction  inci- 
dent to  monolithic  structures,  perpendicular  checks 
will  occur  from  window  sill  to  top  of  window  below. 
This,  however,  is  easily  overcome  in  the  reinforc- 
ing. When  the  concrete  walls  are  completed  they 
94 


are  sprinkled  until  thoroughly  moistened,  when  they 
are  plastered  with  cement  mortar,  floated  nicely  and 
even  with  wood  float.  Are  sometimes  brushed  with 
wire  brush  in  diagonal  direction;  sometimes  laid  in 
blocks  in  imitation  of  stone  blocks.  If  for  dwellings, 
the  walls  are  usually  studded  and  plastered  for  in- 
side finish.  Metal  ties  used  for  hollow  walls  or  in 
some  hollow  blocks  are  objectionable,  and  though 
galvanized  should  have  their  surface  covered  with 
cement  to  prevent  corrosion.  Metal  ties  used  for 
this  purpose,  through  the  capillary  suction  of  mois- 
ture from  outside  wall,  and  through  changing  tem- 
perature, gather  moisture,  and  after  a  time  are 
worthless.  How  injudicious,  a  wall  that  should  last  a 
century,  bound  with  a  tigh,  worthless  after  15  years. 

The  fourth  method  is  a  plastered  exterior  wall, 
with  wood  body. 

Veneered   Plaster. 

This  method  is  coming  into  "use,  especially  in  cot- 
tage construction.  For  this  work  a  frame  is  con- 
structed as  for  wood  house,  only  that  building  is  kept 
back  from  face  of  wall  1  inch,  which  is  taken  up  with 
plaster  coat.  The  sheeting  should  be  nailed  diagonal 
to  studding,  securely  nailed  at  edges.  Strip  outside 
perpendicular  with  plastering  laths;  against  this 
lath  as  for  inside  and  plaster  with  cement  mortar, 
cement,  1;  sand,  2%;  where  metal  lathing  is  used, 
nail  this  against  sheeting  and  plaster  as  on  lath. 
The  surface  may  be  blocked  to  represent  stone.  Can 
be  sanded  or  could  be  finished  with  white  pebbles. 

Silos 

built  from  wood  are  short  lived,  when  filled  owing  to 
the  great  moisture  they  are  so  thoroughly  expanded, 
that  when  empty  they  shrink  and  are  too  open  to 
again  use,  will  collapse  or  blow  over  when  empty. 
Concrete  for  this  work  has  proven  practical  and  is 
used  where  the  best  construction  prevails.  Some  ' 
silos  are  built  above  ground,  others  partly,  while 
others  still  are  entirely  in  the  ground,  the  latter  per- 
haps all  things  considered  are  the  best.  They  are 
usually  built  beneath  basement  of  stables,  or  barn. 
Some  convenient  device  is  constructed  above  them 
by  which  the  contents  can  be  easily  removed  in  feed- 
95  • 


ing,  they  are  built  circular,  and  it  is  imperative  that 
they  must  not  leak.  The  walls  require  no  reinforc- 
ing and  are  built  much  like  cistern.  Where  silos 
project  above  ground  they  are  reinforced  by  heavy 
wire  carried  continuously  around  near  outside  shell 
of  wall,  the  thickness  of  wall  or  shell  would  depend 
on  height,  but  need  not  be  over  6"  at  bottom  and  4" 
at  top  for  height  of  25  feet.  On  the  side  on  which 
the  doors  are  left,  between  doors  the  space  should 
be  reinforced  with  extra  rods,  and  perpendicular  rods 
should  extend  near  side  of  doors  upward  into  the 
continuous  circle  above.  These  openings  are  molded 
with  a  shoulder  on  inside  against  which  a  tight  wood 
closure  is  set  when  filling.  The  form  for  the  wall  can 
be  made  very  economically  by  the  use  of  sheet  iron 
form  %"  thick  and  18"  wide,  and  the  length  required 
for  circumference  one  for  outside  and  one  for  in- 
side face  of  wall.  These  are  held  to  the  size  required 
by  two  flat-headed  thumb  screw  bolts  set  in  slots 
about  8"  long,  one  at  upper  and  one  at  lower  corner, 
clamping  the  lap. 

When  first  set,  fill  carefully  so  as  to  maintain  a 
true  circle,  after  which  the  perpendicular  and  circle 
can  be  easily  kept.  As  the  form  when  full  is  lifted 
only  1  foot,  each  time  allowing  a  lap  of  6  inches, 
keep  top  of  form  level  at  each  set,  when  the  sides 
will  continue  perpendicular.  To  lift  form,  loosen 
thumb  screws;  three  or  four  men  catching  beneath 
will  Itft  it  to  the  height  desired,  holding  it  in  place 
by  inserting  spikes  in  the  concrete.  This  is  con- 
tinued to  top,  when  both  inside  and  outside  are  plas- 
tered smooth  and  dense  against  the  damp  surface. 
Cement,  1;  sand,  3. 


96 


. t6  4 


T/^. 


'2- 


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